I

IAMBLICHOS. See NEOPLATONISM.

IBAS OF EDESSA. Bishop of Edessa from 435 to 449; he was deposed by the “Robber” Council of Ephesus. Reinstated at the Council of Chalcedon in 451, he continued to write polemics against Cyril of Alexandria until his death in 457. His critics claimed his theology leaned toward Nestorianism, which resulted in his condemnation in 553 at the Fifth Ecumenical Council at Constantinople in 553 during the Three Chapters controversy. See also CHRIST, THEOLOGY OF; MONOPHYSITISM.

IBERIA. The term can refer variously to Spain, or to Georgian Iberia in the Caucasus, the sixth-century client state of Persia. There was also a theme with this name created by Basil II, which included Mantzikert. After the Battle of Mantzikert in 1071, the theme was overrun by the Seljuks. See also ANI; ARMY; THEODOSIOUPOLIS.

IBN AL-ATHIR. Arab historian (1160–1233). His Historical Compendium, a history of the Muslim world from the Creation to 1231, is among the greatest historical works of the 13th century. It is particularly useful for Byzantine military affairs in Asia Minor in the second half of the 12th century, for the events of the Third Crusade, and for the conquest of Constantinople by the Fourth Crusade. See also CRUSADES.

IBN BATTUTA. Arab traveler (1304–1377) who journeyed extensively throughout the Islamic world, Asia Minor, and the Crimea. His Travels, composed in 1355, is exceedingly useful for social and economic conditions in early 14th-century Asia Minor. For example, he notes that there were still considerable numbers of Christians in western Asia Minor. In Laodikeia he saw Greek textile workers still at work, and women wearing turbans. In Constantinople he had a personal audience with Andronikos III Palaiologos in late 1331. See also IBN JUBAYR.

IBN HAWQAL. Arab geographer whose 10th-century Picture of the Earth is a historical geography of Muslim and Byzantine lands that includes economic information not found in Byzantine historical sources. For example, he has a description of commerce and taxation in Antalya, and his maps indicate the location of some Byzantine themes. See also ECONOMY; IBN KHURDADHBEH; KOSMAS INDIKOPLEUSTES; TRADE AND COMMERCE.

IBN JUBAYR. Arab traveler, born in Spain. His Travels include a vivid description of the first (in 1183–1185) of two journeys he made to Mecca. For part of that journey he was on board ships from Genoa. Among the valuable information he supplies are descriptions of the Norman court in Palermo, Crusader-occupied Acre, as well as comments on Byzantine relations with the Genoese. See also IBN BATTUTA; SICILY; TRANSPORTATION.

IBN KHURDADHBEH. Arab geographer (died ca. 912). His Routes and Kingdoms (completed ca. 885) offers an important description of the theme system in the ninth century, along with details about thematic troop strengths and pay. The book also offers precise information on the cities, highway system, and fortifications of Asia Minor. For example, it provides details about the main highway that went from the Cilician Gates to the fort of Lulun, and thence, in stages, across Asia Minor to the Sea of Marmara and Constantinople. See also BEACON SYSTEM; DORYLAION; GEOGRAPHY; IBN HAWQAL.

ICON. Greek for “image,” referring to an image of a holy person (e.g., the image of Christ, the Theotokos, a saint, archangel, or apostle). Today the term usually refers to an image painted on a portable wooden panel, but the term can also refer to an image created by other artistic mediums.

Icons were venerated (not worshipped) by prayers, by kissing them and bowing before them (proskynesis), by displaying them in processions, by lighting candles and incense before them. Since icons were believed to give access to the holy person portrayed on them, prayers of intercession were common, and many icons were believed to have miraculous curative and protective powers. Some were believed to have been miraculously created, without human hands (acheiropoieta).

The closeness with which the actual sacred person was attached to the icon is seen in the vita of Daniel the Stylite, which reports that when the saint died his body was placed upright on a board, displayed like an icon, before which people made intercessory prayers. Such veneration could be viewed as idolatry, which is how those who subsequently supported Iconoclasm viewed it. See also ART; MIRACLE; RELICS.

ICONOCLASM. Greek for the “breaking of images,” referring to any attempt to destroy religious images (icons), and referring more specifically to the attempt by certain eighth- and ninth-century emperors to cleanse Byzantium of what they perceived as religious idolatry. Some modern scholarship also sees a connection to the belief of Leo III and subsequent Iconoclast emperors that Arab victories (and natural disasters) were a punishment from God for such idolatry.

Hostility toward religious images was not new. Old Testament prohibitions against idolatry had a continuing influence on the church and probably account for church-supported Iconoclasm prior to 726, the year when Emperor Leo III ordered that the image of Christ above the Chalke of the Great Palace be removed. What was new was imperial support of such prohibitions. A silentium in 730 ordered the general destruction of religious images. The patriarch Germanos I was forced to resign, and Leo III, intent on demonstrating his control over the church, replaced him with the Iconoclast Anastasios.

Severe persecution began during the reign of Constantine V, who rejected even the veneration of relics, arguing that the Eucharist was the only true image of Christ. This theology of the icon was formulated at the Council of Hieria in 754. Persecution declined during Leo IV’s reign, and it was condemned in 787 at the Ecumenical Council at Nicaea, convened by Irene to restore icons. With this the first period of Iconoclasm (726–787) came to a close. Its revival in the ninth century under Leo V and Theophilos constituted a second period (815–843). Theophilos’s widow Theodora and her minister Theotikstos condemned Iconoclasm for the last time in 843, when this imperial heresy came to an end.

From 726 to 843 the Iconoclast movement was a potent and disruptive force in Byzantium. Usurpers and rebels like Artabasdos, Michael Lachanodrakon, and Thomas the Slav championed the cause of images against Iconoclast emperors who stripped the church of its Iconophile bishops, persecuting those, like Euthymios of Sardis who resisted. During Constantine V’s reign, it seemed as if the state was at war against the institution of monasticism, which supported icon production and veneration. The last Iconoclast emperor, Theophilos, also singled out monks for punishment, including the two icon painters Theodore and Theophanes Graptos.

The failure of Iconoclasm was partly due to the widespread popularity of icons among clergy, monks, and ordinary citizens, many of whom venerated small icons in private during the reigns of Iconoclast emperors. Theophilos’s own wife Theodora did this within the Great Palace. Monks, who suffered the most from persecution, are particularly celebrated in the history and hagiography about Iconoclasm. See also CHARISTIKION; HADRIAN I; SAINT.

ICONODULES. See EUTHYMIOS OF SARDIS; ICONOPHILES; STEPHEN THE YOUNGER.

ICONOPHILES. From the Greek word that means “image-lovers” or “image-servants.” The term basically means someone (an Iconophile, also called an Iconodule) who venerates religious icons, and dates from the period of Iconoclasm, when the term was used to distinguish those who defended the veneration of icons as holy objects. By contrast, Iconoclasts considered religious icons idolatrous and sought to destroy them, persecuting Iconophiles who actively opposed icon-destruction. See also CHRIST, THEOLOGY OF; ICONOSTASIS; RELICS.

ICONOSTASIS. Greek for “image-stand,” which can refer to freestanding constructions housing icons. One sees these in the countryside of modern Greece, often erected for commemorative purposes (e.g., to mark the site of a former church). The term also refers to the tall wooden partition pierced by three doors, decorated with icons, which separates the bema from the naos of a church. This partition developed from the earlier templon, a low balustrade found in early Byzantine churches. See also BASILICA.

IGNATIOS. Patriarch of Constantinople from 847 to 858, and again from 867 to 877; son of the former Emperor Michael I Rangabe; saint. Ignatios’s struggle with Photios dominated his two periods of tenure as patriarch of Constantinople.

This struggle is complex in terms of both its causes and its consequences. It provoked an international crisis with the papacy, created a serious internal conflict within the Byzantine church, and became part of the political controversy that intersected with the murder of Michael III by Basil I. The struggle began in 858, when Ignatios was deposed by Bardas (the powerful advisor to Michael III). Bardas’s favorite for this post, the scholar Photios, was made patriarch in Ignatios’s place.

This immediately Split the church into two opposing camps. The supporters of Ignatios protested Photios’s uncanonical appointment. Pope Nicholas I, intent on asserting his authority over the Byzantine church, convoked a council in Rome that demanded that Ignatios be reinstated. In turn, a church council was convened in Constantinople in 867 that condemned and anathematized Pope Nicholas I; it further condemned the western church’s addition of the filioque to the creed. Relations between the Byzantine and western churches, already strained over their competition for the allegiance of new converts in Moravia and Bulgaria, became hostile.

Later that same year (867) Basil I murdered Michael III and assumed the imperial throne. Because Basil needed papal support in Italy, where Byzantine troops were operating against the Arabs, he reinstated Ignatios (867). He then convened a church council in Constantinople in 869–870, attended by papal legates of Pope Hadrian II. This council formally condemned Photios and declared Ignatios reinstated. A final twist to this complex affair is that when Ignatios died in 877, Photios was reinstated as patriarch of Constantinople by Basil I. See also LITURGY; MISSIONS; THEOLOGY.

IGNATIOS OF SMOLENSK. His journey from Moscow to Constantinople in 1389, and his subsequent residence on Mount Athos and in Thessalonike, are recorded in three works of meticulously descriptive detail. Among the important information he provides is an account of the coronation of Manuel II Palaiologos in 1392.

IGNATIOS THE DEACON. Prolific ninth-century writer, whose works include the biographies (vitae) of patriarchs Tarasios and Nikephoros I, as well as those of Gregory of Dakapolis and George of Amastris. He also wrote poetry, a lampoon of Thomas the Slav, letters, funeral elegies, and other works (including now lost ones) listed in the Souda. See also LITERATURE.

IGOR. Prince of Kiev from 912 to 945, succeeding Oleg. Byzantium remembered him primarily for his expeditions against Constantinople in 941 and in 943 (or 944). In the first attack the Rus fleet was destroyed by Greek Fire. The second attack was met on the Danube with offers of a new commercial treaty (945), which the Rus agreed to. After Igor’s death at the hands of Slavic tribesmen his wife Olga ruled Kiev during the minority of their son Svjatoslav. See also TRADE AND COMMERCE.

IKONION. City (modern Konya) in Pisidia, on the Anatolian plateau of Asia Minor. Frequently the object of Arab assaults, Ikonion became capital of the Sultanate of Rum after its conquest by the Seljuks in 1084.

ILLOS. Powerful Isaurian patrikios and magister militum who helped Zeno recover his throne. Verina attempted to assassinate Illos, but she failed. Illos demanded that Verina be imprisoned, and Zeno complied. The empress Adriadne’s own attempts to assassinate him also failed. These events prompted Illos to revolt in 484, gaining support from pagans and Orthodox alike, who were hostile to Zeno’s pro-Monophysite policy. Defeated in battle, he held out for four years in an Isaurian fortress before being captured in 488 and beheaded. See also MONOPHYSITISM.

ILLUSTRIS. The highest of three titles given to members of the senate, and high administrators, from the fourth century onward. Below illustris (illustres is the plural) were the titles of clarissimus and spectabilis. When bestowed on officeholders, any one of these titles automatically guaranteed a place in the senate. From the middle of the sixth century, the illustres were raised to gloriosi, and the spectabiles were raised to join the illustres. See also BUREAUCRACY.

ILLYRICUM. A fourth-century prefecture in the Balkan Peninsula comprising Pannonia, Macedonia, and Dacia. It was divided into two parts after 395. Justinian I transferred the capital of the prefecture to Justiniana Prima, a city he built ca. 530 near his birthplace. However, after Justinian I’s death in 565, Illyricum suffered invasion by barbarians, including Lombards, Avars, Slavs, Serbs, and Croats. In the seventh century many inland sites were abandoned, including Justiniana Prima. The ninth-century themes of Dyrrachion and Thessalonike were created from what survived of the former prefecture. See also DIOKLEIA; LEO III.

IMAD AL-DIN. Historian; Abbasid diplomat. Friend of both Nur al-Din and Saladin, his works are among the most important contemporary sources for Saladin’s career. He also wrote the earliest history of the Seljuks, which offers detailed information about the initial Seljuk conquests in Asia Minor, including an account of the Battle of Mantzikert.

IMBROS. Island in the Aegean Sea, northeast of Lemnos, near the entrance to the Hellespont. It was in Byzantine hands until 1204, when Venice obtained it. The Gattilusio family controlled it from 1354, but within a century it had reverted back to Byzantium. It fell into the hands of the Ottoman after the fall of Constantinople in 1453. Mehmed II gave the island as an appanage to Demetrios Palaiologos, his son-in-law, in 1460. The historian Michael Kritoboulos was a native of the island. See also ABYDOS; GALLIPOLI; NAVIGATION; SEA OF MARMARA; TENEDOS; TRADE AND COMMERCE.

INDIA. Until the seventh century Byzantine trade with India was almost entirely in the hands of merchants from Persia, Axum, and Himyar, who conveyed spices, precious gems, and incense to Ceylon, ports along the Red Sea, and to Persia, by overland caravans. The Byzantine solidus was the preferred coinage for trade, according to Kosmas Indikopleustes, a Byzantine merchant from Alexandria who offers the most detailed account of India, including trade with the country and its people.

The fascination India held for the Byzantines is evident in another sixth-century work entitled Indian Animals by Timothy of Gaza. The expansion of the Arabs in the seventh century ended Byzantine contacts with India, but Byzantine interest continued, as evidenced by the romance of Barlaam and Ioasaph. See also TRADE AND COMMERCE.

INDICTION. The term originally meant a levy of foodstuffs for the imperial government. From 1 September 312 onward it was used to refer to a 15-year tax cycle. From 537 all imperial documents were dated by the year of the Indiction (first year, second year, etc.), although by itself this means little to modern historians unless the first year of the cycle can be related to a calendar year.

An Indiction year ran from 1 September to 31 August, dates suited to a Mediteranean climate where cereal crops were harvested in late May/early June, giving peasant farmers enough time to sell off their surplus for the money needed to pay their taxes by 1 September. See also CHRONOLOGY; TAXATION.

INDUSTRIAL PRODUCTION. Industrial production in Byzantium was in state factories, many of them in Constantinople, which produced goods vital to the state. These factories were essentially larger versions of the more ubiquitous smaller, private artisan workshops found in cities and towns. State factories used both free labor and slaves, but also criminals who were serving out their sentences. Such factories were located in urban areas and produced what the state required, notably weapons, silk (needed for court attire), textiles (of wool, linen, and cotton), coinage, and jewelry. Other required goods that the state needed, such as stone and marble, pottery, bread and other victuals, it ensured by regulating the urban guilds. The Book of the Eparch, probably issued by Leo VI, offers information about the regulation of guilds. See also ECONOMY; HIGHWAYS AND ROADS; TRADE AND COMMERCE; TRANSPORTATION.

INFANTRY. See ARMY.

INNOCENT III. Pope from 1198 to 1216 whose efforts toward union of the churches reached an unforeseen conclusion in the Fourth Crusade’s conquest of Constantinople. Innocent lost control of the Fourth Crusade to the Venetians, who used the Crusade to capture the Christian city of Zara in 1202. For this, the pope excommunicated the Crusaders, including the Venetians. He then lifted the ban on the Crusaders to allow them to collaborate with the (still excommunicated) Venetians. Innocent’s subsequent wait-and-see attitude seemed to bear fruit when the Fourth Crusade conquered Constantinople in 1204. Thereafter, despite attempts at persuasion and even the forcible inclusion of the Byzantine church within the Latin church, real union of the churches was never achieved. See also CHURCH SCHISM OF 1054; DANDALO, ENRICO; VENICE.

INSTITUTES. Handbook of civil law for law students; part of the Corpus Juris Civilis, with the authority of law. It was prepared by Tribonian and two other jurists, Theophilos and Dorotheos, while they were working on the Digest. Essentially, it updated the Commentaries of Gaius, the great second-century jurist, in a way that made it a primer for the remainder of the Corpus Juris Civilis. The Institutes and the Digest were published in 533, necessitating a revision of the 529 Codex Justinianus, which was completed in 534. See also ECLOGA.

IOANNINA. City in Epiros situated on a fortified promontory that juts into Lake Pamvotis, against the backdrop of the highest peaks of the Pindos range. Apparently founded by Justinian I, it was captured by the Normans in 1082, but fell under the control of the Despotate of Epiros from 1205 to 1318, after which it reverted to the Byzantines until around 1348 when it was conquered by Stefan Urosh IV Dushan. In 1430 the Ottomans occupied it. See also GREECE.

IONIAN SEA. That part of the Mediterranean Sea between Greece and Italy. It is connected to the Adriatic Sea by the Strait of Otranto. The seven principal Ionian islands are Kerkyra, Paxoi, Levkas, Ithaka, Kephalonia, Kythera, and Zakynthos. See also TARANTO.

IRAN. See PERSIA.

IRENE. First empress to rule Byzantium in her own right (797–802); restorer of icons. In state documents she was referred to as emperor (basileus), not empress. She was regent for Constantine VI from 780 to 790, during which time she was aided by the eunuchs Staurakios, logothetes tou dromou, and Aetios, protospatharios. In 783 Staurakios launched an expedition against the Slavs in Greece, and in 787 he aided Irene in the restoration of icons at the Seventh Ecumenical Council at Nicaea.

In 790 Constantine VI removed Irene and her advisors, but they returned to the palace in 792 and plotted Constantine VI’s overthrow and blinding (797). Her negotiations to marry Charlemagne in 802 were stymied by Aetios and resulted in her overthrow by Nikephoros I that same year. See also ELPIDIOS; TARASIOS; WOMEN.

IRENE DOUKAINA. Wife and empress of Alexios I Komnenos and mother of Anna Komnene, John II Komnenos, and seven other children. Anna Komnene describes her beauty as equal to the goddess Athena. Irene frequently attended Alexios I on military campaigns, but back in Constantinople her role was diminished by the influence of Alexios I’s mother, Anna Dalassene. She retired to a convent in 1118, when John II Komnenos succeeded his father. See also DOUKAS, JOHN; WOMEN.

IRENE-YOLANDA OF MONTFERRAT. She married Andronikos II Palaiologos in 1284, after the death of his first wife, Anna of Hungary. By this marriage, the house of Montferrat surrendered its claims to the crown of Thessalonike, which Boniface of Montferrat originally held. Yolanda, who took the Greek name Irene, bore three sons, John, Theodore, and Demetrios. She also bore a daughter, Simonis, who was married to Stefan Urosh II Milutin.

When Andronikos II refused her request to divide the empire equally among his sons, including his first born Michael IX, she took her own sons and went to live in Thessalonike. There she intrigued against her husband with Milutin, the Catalan Grand Company, and Charles of Valois. She died in Thessalonike in 1317. See also WOMEN.

ISAAC I KOMNENOS. Emperor from 1057 to 1059. After overthrowing Michael VI his brief reign held the promise that Byzantium’s military power might be restored. However, the rapid pace of his reforms alienated the civil bureaucracy, whose pensions and salaries were cut drastically. The new tax surcharges on the provinces and the collection of unpaid taxes did not make him popular.

Patriarch Michael I Keroularios turned against him when he revived the anti-monastic legislation of Nikephoros II Phokas and appointed Michael Psellos as his chief minister. Isaac removed Keroularios and appointed Constantine III Leichoudes in his place, which alienated the church. Threats from the Pechenegs and Hungarians were repulsed, but Isaac became increasingly isolated, and when he fell ill Psellos persuaded him to retire to a monastery. See also STYLITE; TAXATION.

ISAAC II ANGELOS. Emperor from 1185 to 1195, and again from 1203 to 1204. His general Alexios Branas repulsed William II’s Normans in 1185. However, thereafter his reign was characterized by drift and decline. While he sold state offices and renovated the Great Palace, Alexios Branas revolted (1187), and had to be defeated by Conrad of Montferrat. In that same year an expedition failed to recover Cyprus from self-proclaimed emperor Isaac Komnenos. The Vlachs and Bulgarians revolted under Peter of Bulgaria and Asen I. In 1190 Isaac II vainly resisted the passage of Frederick I Barbarossa during the Third Crusade, in obligation to Saladin. Frederick I’s occupation of Adrianople brought Isaac to heel.

In 1195 Isaac was overthrown and blinded by his brother Alexios III Angelos. Eight years later he was placed briefly on the throne with his son Alexios IV Angelos, only to be overthrown the following year by Alexios V Doukas. See also FOURTH CRUSADE.

ISAAC KOMNENOS. Self-proclaimed emperor of Cyprus from 1184 to 1191. With forged papers, this great-nephew of Manuel I Komnenos gained control of the island and declared it independent from the government in Constantinople. Without a fleet, Andronikos I Komnenos was unable to put down the revolt. In 1187 Isaac II Angelos sent a fleet to recover the island, but Margaritone, admiral of Isaac Komnenos’s ally William II of Sicily, defeated it. Isaac ruled Cyprus tyrannically until 1191, when Richard I Lionheart captured the island.

ISAURIA. See ISAURIANS.

ISAURIAN DYNASTY. This dynasty ruled Byzantium from 717 to 802. Theophanes the Confessor reports that the first Isaurian emperor, Leo III, was an Isaurian, though in reality he came from Germanikeia. Nevertheless, the name has stuck for this dynasty, a dynasty closely tied to Iconoclasm and to the struggle with the Arabs in Asia Minor.

ISAURIANS. The backward, near barbarian tribesmen of Isauria, a mountainous region in the southern interior of Asia Minor. Isauria was the only part of the empire that could furnish large numbers of native, warlike soldiers, and Leo I recruited them in large numbers to counteract the German control of the eastern army in the guise of Aspar and the Ostrogoths.

In 466 Leo married his daughter Ariadne to the Isaurian chieftain Tarasicodissa, who took the name Zeno. During Zeno’s reign (474–491) the ascendancy of the Germans was replaced by Isaurian influence. When Zeno died, the Isaurians were suppressed by Anastasios I. After the last of the rebel leaders were killed in 497, large numbers of Isaurians were transported to Thrace, where they were settled in colonies.

ISIDORE I BOUCHEIRAS. Patriarch of Constantinople from 1347 to 1350. He and his two successors (Kallistos I and Philotheos Kokkinos) were fervent Hesychasts and friends of Gregory of Sinai. Like Kallistos I, he was also a pupil of Gregory of Sinai.

In 1347 Isidore performed the second coronation of John VI Kantakouzenos, who had been crowned initially in Adrianople the previous year. This second coronation was carried out without the crown jewels, for they were still pawned to Venice, and without the traditional setting of Hagia Sophia, due to its dilapidated state. Such was the poverty of the Byzantine state at the time.

ISIDORE OF KIEV. Metropolitan of Russia who signed the decree of the union of the churches at the Council of Ferrara-Florence in 1439. A former Greek monk at Mistra, Isidore had previously represented John VIII Palaiologos at the Council of Basil in 1434. Upon his return to Moscow in 1440 Grand Duke Basil II threw him into prison, rejecting both union with the papacy, and any further ties with Byzantium. Isidore escaped to the West, where he became a papal ambassador for Nicholas V, in which capacity on 12 December 1452 he proclaimed church union in Constantinople.

When Constantinople was captured by the Ottomans in 1453, he exchanged the red robes of a cardinal for the clothes of a beggar in order to escape death. A Genoese merchant later ransomed him.

ISIDORE OF MILETUS. Architect, engineer, and mathematician who taught physics at the universities of Alexandria and Constantinople, and who assisted Anthemios of Tralles in the planning and construction of Hagia Sophia in Constantinople, the great church commissioned by Justinian I. Isidore is not to be confused with his nephew, Isidore the Younger. See also ARCHITECTURE; DOME; SCIENCE; TECHNOLOGY.

ISIDORE OF SEVILLE. Bishop of Seville (ca. 600–636) and compiler of the standard encyclopedia of knowledge for the West in the Middle Ages, the Etymologies. His History of the Reigns of the Goths, Vandals, and Suevi is a chronicle of events in Spain from the fourth to seventh centuries that includes some information about Byzantine affairs outside of Spain.

ISIDORE THE YOUNGER. Nephew of Isidore of Miletus who rebuilt the dome of Hagia Sophia in Constantinople after it collapsed in 558, raising the height of the original dome by about seven meters. Although subsequently damaged (in 989 and in 1346) and repaired, essentially it is Isidore’s dome that visitors to Hagia Sophia view today. See also ARCHITECTURE; SCIENCE; TECHNOLOGY.

ISLAM. Arabic term meaning “submission” (to God), the essential message of the religion founded by Muhammad the Prophet. A follower of Islam is called a Muslim (or Moslem), which means “one who submits.” For Byzantines Islam remained the heresy of their Muslim opponents (initially the Arabs). Polemics against Islam included attacks on its strict monotheism, which denied the Incarnation of Christ.

Byzantine interaction with Islam was primarily through armed struggle that went on from the Arab victory at the Battle of the Yarmuk River in 636 until the Ottoman conquest of Constantinople in 1453. By 642 the Arabs had conquered Syria, Palestine, Egypt, and Mesopotamia, the most valuable Byzantine provinces. Thereafter, until the 10th century, the military struggle with the Arabs focused on Asia Minor, which Byzantium reorganized into themes.

The Byzantine offensives of the 10th and 11th centuries in Mesopotamia and Syria lasted until the Seljuk victory at the Battle of Mantzikert in 1071. The Seljuks revived Islamic militancy in Asia Minor, much of which was lost to Byzantium by the time of Alexios I Komnenos, who, with the aid of the First Crusade, was able to recapture Nicaea in 1097. Subsequent attempts to enlarge Byzantine possessions in Asia Minor were dealt a blow after the Battle of Myriokephalon in 1176. The Fourth Crusade’s capture of Constantinople in 1204, and the Latin Empire established there until 1261, was another lethal blow.

After Byzantium was restored to its capital in 1261, it was too weakened to resist the final Islamic threat in the form of the Ottomans, whose first major victory over Byzantium in Asia Minor was in 1302 at the Battle of Bapheus. The Ottoman conquest of Constantinople came much later in 1453, but by the middle of the 14th century the writing was on the wall, so to speak.

Diplomacy was another form of interaction, especially with the Abbasid Caliphs of Baghdad. The Caliph Mamun was particularly interested in ancient Greek scientific texts, and tried to persuade Leo the Mathematician to come to Baghdad. The emperor Theophilos dashed that scheme, but was himself under the cultural influence of Baghdad, as his Bryas Palace is said to have demonstrated. Islamic textiles and fine pottery also had their influence on Byzantium, as did a kind of debased, imitative Arabic writing called “Kufic,” which was used to decorate luxury items and even Byzantine churches. Islamic-style silk caftans could be seen at the Byzantine court from the ninth century onward. The 14th-century donor-portrait of Theodore Metochites, painted in fresco on the walls of the Chora Monastery, in Constantinople, shows Metochites with what appears to be an Ottoman-style turban on his head. See also ARMY; BEACON SYSTEM; CHRIST, THEOLOGY OF; HARUN AL-RASHID.

ISTRIA. Mountainous peninsula in the northern Adriatic Sea between the gulfs of Trieste and Fiume. The Ostrogoths seized it in 493. The forces of Justinian I reconquered it in 539. The Lombards, who invaded Italy in 568, took over much of Istria by the end of the sixth century. Nevertheless, the coast remained under Byzantine control even after the fall of the Exarchate of Ravenna in 751. In 788 Charlemagne, having completed his conquest of Longobardia, extended his conquests farther to the east and seized Istria. In the ninth century Frankish domination was replaced by that of Venice.

ITALY. Beginning with the tetrarchy, the political importance of Rome declined with the establishment of new imperial residences outside Rome. For example, Maximian governed from Milan. This process increased with the foundation of Constantinople in 330, and with the creation of eastern and western co-emperors later in the fourth century. Milan and, after 402, Ravenna, were favored residences of the western emperors.

Invasions and conquest contributed to Italy’s general decline. Invasions by Alaric’s Visigoths culminated in their sack of Rome in 410. Italy suffered further depredation by the Vandals, who again sacked Rome in 455. The overthrow of Romulus Augustulus in 476 and the conquest of Ravenna by the Ostrogoths in 493 created an Ostrogothic state.

Justinian I’s reconquest of Italy from the Ostrogoths produced a war that lasted from 535 to 562. What resulted was the devastation of Milan, as well as the depopulation of Rome and of much of Italy. During the midst of this war, a force of Franks and Alemanni invaded Italy in 553–554 and was annihilated by Narses. Not long after the war’s conclusion, Justinian I’s victory was overturned by the Lombard invasion of Italy in 568. Thereafter, except for Ravenna and Venice in the north, Byzantium was relegated to southern Italy.

After 568, Rome began to fend for itself under the leadership of the papacy, while Byzantine possessions were reorganized as the Exarchate of Ravenna. However, in 751 the Lombards captured Ravenna, and not long after (in 787) northern Italy was conquered by Charlemagne. Byzantine possessions in southern Italy were frequently endangered by Arab raids and Lombard revolts. This required occasional military intervention, for example, by Basil I, by katepano Basil Boiannes, and by George Maniakes. However, it was the Norman expansion in southern Italy, beginning in 1016 and culminating in 1071 with the conquest of Bari, which ejected Byzantium from Italy. See also ADRIATIC SEA; BARBARIANS; DALMATIA; MEDITERRANEAN SEA; VENICE.

IVAJLO. Tsar of Bulgaria from 1278 to 1279. He overthrew Constantine Tich, and tried to save Bulgaria from the depredations of the Mongols. He was victorious over the Mongols, but not over Michael VIII Palaiologos, who intervened militarily to support the claim of his son-in-law John Asen III to the throne. When Ivajlo turned to the Mongols for aid, they murdered him.

IVAN III. Grand prince of Moscow from 1462 to 1505. He married Sophia Palaiologina, who was daughter of Thomas Palaiologos, last despot of the Morea, and niece of Byzantium’s last emperor, Constantine XI Palaiologos. Ivan III displayed the two-headed eagle on his seals, introduced Byzantine ceremonial to his court, and encouraged the view that Moscow had inherited the mantle of Byzantium as defender of Orthodoxy.

IVAN ALEXANDER. Tsar of Bulgaria from 1331 to 1371 who took advantage of the Byzantine civil war of 1341–1347 to enlarge his domains with Philippopolis and other cities. His alliances with the Ottomans and with Stefan Urosh IV Dushan had the similar aim of territorial gain at Byzantine expense. See also GREGORY OF SINAI; JOHN V PALAIOLOGOS; JOHN VI KANTAKOUZENOS.

IVANKO. Nephew of Asen I who assassinated Asen I in 1196. He tried to hold Turnovo against Asen I’s brother Peter, but when promised Byzantine support failed to materialize, he fled Bulgaria for Constantinople. There he married into the imperial family of Alexios III Angelos and was given Philippopolis to administer. Deserting Alexios III in 1198, he briefly set up an independent principality in Rhodope and central Thrace before being captured in 1200 by a ruse and executed. See also ANGELOS DYNASTY.

IVERON MONASTERY. Founded on Mount Athos in 979 for monks from Iberia (Georgia), hence the name. It became a center of Georgian culture with a renowned scriptorium. Its katholikon, completed in 983 and contemporary with the katholikon at the Great Lavra, is among the oldest churches on Mount Athos. See also ASCETICISM; MONASTICISM.

IVORY. Used extensively for diptychs, icons, book covers, and other objects, including furniture decoration, from the fourth through sixth centuries. The Arab conquest of North Africa seems to have curtailed Byzantine access to ivory, for it became much more rare after the sixth century. Some of the most memorable works of Byzantine art are in ivory, for example, the famous Barberini Ivory in the Musée du Louvre in Paris that depicts Anastasios I (or Justinian I), and the ivory panel in the Museum of Fine Arts in Moscow depicting Christ crowning Constantine VII Porphyrogennetos.