U

ULDIN. See GAINAS.

ULFILAS. Arian missionary to the Goths. He was captured by the Goths and spent several years among them before they sent him on an embassy to Constantinople. There, in 341, he allowed Eusebios of Nikomedeia, who was an Arian, to consecrate him as bishop.

Subsequent missionary activity among the Goths included his translation of the Bible into Gothic, for which purpose he created a Gothic alphabet. This, the first vernacular Bible, undoubtedly strengthened Arianism among the Goths. Nevertheless, Arianism proved to be an obstacle to their acceptance as citizens of the empire, once Nicene Orthodoxy became the official state religion under Theodosios I. See also BARBARIANS; MISSIONS.

UMAR. Caliph from 634 to 644, succeeding Abu Bakr. It was during his reign that the Arabs conquered Byzantium’s eastern provinces. Syria fell to Khalid in 636, after the Battle of the Yarmuk. In 638 Jerusalem was surrendered by its patriarch Sophronios after a lengthy siege. Mesopotamia was in Arab possession by 640. Alexandria was captured in 642, along with the remainder of Egypt, and much of Cyrenaica was in Arab possession by 644 when Umar was assassinated.

UMAR, EMIR OF MELITENE. See MELITENE; MICHAEL III; PE-TRONAS.

UMAR BEG. See AYDIN.

UMAYYAD CALIPHATE. Dynasty of Caliphs founded by Muawiya in 661, ending the civil war with Ali (son-in-law of Muhammad the Prophet) that had erupted after the assassination of Uthman in 656. The Caliphate’s capital was Damascus.

Until the Battle of Akroinon in 740 the Umayyads maintained the offensive against Byzantium at sea, and in Asia Minor, besieging Constantinople twice (674–678; and in 717–718 under Maslama). The Caliphate was overthrown in 750 by the Abbasids, but one member of the Umayyads escaped to Spain to found the Umayyad Caliphate at Cordoba, which lasted until 1031.

UNION OF THE CHURCHES. The separation of the eastern and western churches had its origins as far back as the foundation of Constantinople in 330, which diminished the importance of Rome. This separation also had its origins in the Council of Chalcedon, which seemed to threaten the stature of the bishop of Rome, as well as in the gradual diminution of Byzantine power in Italy beginning with the Lombard invasion of 568.

Differences in ritual and practice were also important, including the western use of azyma, the filioque, and papal primacy. The intolerance of western church reformers in the 11th century was reflected in the person of Humbert, who played a chief role in instigating the church schism of 1054.

The conquest of Constantinople by the Fourth Crusade made reconciliation with the West impossible. Moreover, efforts to heal the schism were intertwined with the Byzantine state’s need of western military aid against the Seljuks and Ottomans; inevitably this meant a Crusade, which only the papacy could proclaim. The union of the churches proclaimed at the Council of Lyons in 1274, and subsequently at the Council of Ferrara-Florence in 1439, failed to gain popular support, much less any realistic military aid, as seen in the failed Crusade of Varna. See also AKAKIAN SCHISM; EUCHARIST; GREGORY VII; LITURGY; ORTHODOXY; POPE.

URBAN II. See FIRST CRUSADE.

UTHMAN. Caliph from 644 to 656; he succeeded Umar. Under him, the Arabs completed much of their westward march across North Africa, defeating the Byzantine eparch Gregory in 647. In the eastern Mediterranean equally important Byzantine reverses occurred. In 648 an Arab fleet invaded Cyprus. In 655, off the coast of Lycia, in the first major naval battle with the Arabs, Constans II lost his fleet and almost his life. However, further expansion was stalled for several years by the civil war that broke out upon Uthman’s assassination in 656.

UTRIGURS. Turks from the Eurasian steppe who migrated westward, by the late fifth century settling beyond the Don River to the east of the Sea of Azov. Justinian I used them as a check on their neighbors, the Cotrigurs. The Avars briefly subjected them in the 560s, and they were subsequently incorporated into Bulgaria.

UZES. Confederation of Turks from the Eurasian steppe. They fled the advancing Cumans by following the Pechenegs across the Danube in 1064. After wreaking havoc as far south as Greece, plague and starvation forced them to retreat back across the Danube. Most eventually settled among the Pechenegs and Rus. Others were accepted into the Byzantine army as mercenaries.

At the Battle of Mantzikert in 1071, the army of Romanos IV Diogenes included Uzes, whose loyalty was suspect, given their close ethnic affinity to the Seljuks. Indeed, some Uzes defected to Alp Arslan during the battle. See ASIA MINOR; BALKAN PENINSULA; BARBARIANS.