1017: Norman knights join anti–Byzantine uprising in Apulia, as mercenaries.
1018: Byzantines crush uprising in battle at Cannae. Some Normans remain in Italy as mercenaries with local rulers.
1025: Death of Basileus Basil the Bulgar Slayer; Byzantium enters period of decline.
1029: Rainulf, a Norman knight, awarded a fief at Aversa; it becomes magnet for additional knight-adventurers.
1035: William and Drogo of Hauteville arrive in Italy (approximate).
1038: Byzantines launch campaign into Muslim Sicily. Normans serve as mercenaries.
1041: Norman adventurers join Lombard rebels; seize Melfi from Byzantines. Rebels win battles at Olivento, Montepeloso; begin expansion.
1042: Argyrus selected to lead rebellion, but deserts to Byzantines. Byzantine counter-offensive under Maniakes fails.
1043: Election of William of Hauteville as Count and leader of rebel/Norman forces, as vassal to Guaimar of Salerno. Norman leaders divide Apulia into spheres of influence at Melfi, continue to expand their lands.
1044: Guaimar and William lead raid into Calabria.
1046: William dies; is succeeded as Count of Apulia by his brother Drogo.
1047: Emperor Henry III comes to Italy; invests Drogo as imperial vassal. Robert Hauteville arrives in Italy.
1048: Humphrey Hauteville defeats Byzantines at Tricarico, opens up Calabria to expansion. Robert sent to Scribla in Calabria.
1049: Leo IX elected pope. Holds synod at Melfi; seeks to restrain Norman excesses.
1051: Drogo assassinated; succeeded by Humphrey Hauteville. Pope Leo tries to form anti–Norman alliance.
1052: Guaimar of Salerno assassinated. Normans under Humphrey throw out usurpers, put Guaimar’s son Gisulf on throne.
1053: Pope Leo leads punitive army against Normans. Gisulf remains neutral. Pope defeated at Civitate; acknowledges Norman territorial gains in Italy. In Sicily, Kalbite dynasty expires and central government breaks down, while Zirid protectors in Tunisia face invasion and civil war.
1054: Schism with eastern Church. Pope Leo dies and is replaced by Victor II. Geoffrey, Mauger and William Hauteville arrive in Italy. Normans continue expansion in Apulia.
1055: Humphey establishes William on land seized from Salerno, as Count of the Principata.
1056: Emperor Henry III dies; replaced by infant son Henry as King of the Germans.
1057: Humphrey dies; succeeded as Count by Robert. Roger Hauteville arrives; joins Robert on campaign in Calabria. Pope Victor dies; succeeded by Stephen IX, who forms anti–Norman alliance.
1058: Pope Stephen dies; rival popes elected. Richard of Aversa seizes Capua from Lombard ruling house. Roger and William Hauteville rebel against Robert.
1059: Normans under Richard of Capua march on Rome, install Nicholas II as pope; he reforms papal selection process to eliminate imperial role.
1059: Robert and his brothers reconcile; Robert continues to expand lands in Calabria.
1059: Pope holds synod in Melfi; invests Richard in Capua, Robert in Apulia, Calabria and Sicily.
1060: Robert marries Lombard princess, Sichelgaita of Salerno.
1060: Robert and Roger campaign in Calabria; seize Taranto, Brindisi and Reggio.
1060: Byzantines counterattack; besiege Melfi.
1061: Byzantine offensive checked. Robert and Roger invade Sicily; capture Messina.
1061: Pope Nicholas dies, Norman forces assure investiture of Nicholas II over rival.
1062: Robert and Roger fight over division of land and authority.
1061: Zirids send relief army to Sicily. Roger besieged at Troina.
1063: Roger breaks siege; defeats Muslim army at Cerami.
1064: Robert leads army to Sicily; he and Roger besiege Palermo unsuccessfully.
1064: Robert’s barons in Apulia revolt.
1066: Barons’ revolt continues; Abdul Kare leads Byzantine army into Apulia.
1066: William the Bastard, Duke of Normandy, invades England.
1067: Basileus Constantine dies; Byzantine support for barons’ rebellion dries up.
1068: Robert defeats last rebels; begins siege of Bari.
1068: Roger wins battle at Menzel el Amir. Zirid troops leave Sicily.
1071: Bari surrenders. Robert leads army and fleet to besiege Palermo.
1071: Byzantines suffer major defeat by Seljuk Turks, at Manzikert.
1072: Palermo surrenders. Norman barons in Apulia rebel again.
1073: Gregory VII elected pope on death of Alexander.
1073: Robert defeats last rebels; falls gravely ill. He is chosen as protector of Amalfi.
1074: Robert concludes marriage alliance with Byzantium; his daughter Helen to wed son of Basileus Michael.
1074: Pope Gregory attempts to raise army against Normans.
1075: Roger concludes truce with Zirids; begins to trade with African states.
1076: Conflict between papacy and empire heats up over Church reform and authority. Henry faces Saxon revolt and submits to pope at Canosa.
1077: Robert and Richard of Capua form alliance to capitalize on papal-imperial split.
1078: Robert besieges Salerno successfully; expels Gisulf and Lombard ruling house.
1078: Apulian barons engage in short rebellion against Robert.
1078: Richard of Capua dies.
1079: Roger captures Taormina.
1080: Henry defeats Saxon rebels; turns to Italy. Pope Gregory seeks Norman support.
1080: Gregory invests Robert, at Ceprano, in the lands granted by Nicholas and accepts his control of lands seized since then.
1081: Robert and his son Bohemund invade Byzantine province of Illyria.
1081: Alexius Comnenus seizes Byzantine throne; leads army against Norman invasion.
1081: Normans win battle at Durazzo, advance into Macedonia.
1082: Henry invades Italy; besieges Pope Gregory in Rome.
1082: Apulian barons revolt again; Robert returns to Italy to combat rebellion.
1083: Norman army besieges Larissa, but is driven off by Basileus Alexius.
1083: Robert defeats rebels.
1084: Henry has antipope elected in Rome; has himself crowned emperor.
1084: Robert leads army on Rome; lifts siege of Pope Gregory. Rome sacked by Norman army, and Gregory obliged to leave Rome with Robert.
1084: Robert returns to Illyria to resume campaign.
1085: Pope Gregory dies in Salerno.
1085: Robert dies on campaign. His second son Roger Borsa succeeds, and Bohemund goes into revolt.
1085: In Spain, Muslims lose Toledo to emergent state of Castile.
1086: Roger wins naval battle at Syracuse; captures city.
1087: Roger captures Agrigento and Castrogiovanni.
1089: Bohemund and Roger Borsa partition Apulia; Bohemund becomes Prince of Taranto.
1090: Butera and Noto surrender, last Muslim-controlled towns in Sicily.
1097: Bohemund departs on First Crusade. Roger Borsa becomes overlord of Capua.
1101: Roger Hauteville dies, and is succeeded by his son Simon.