1071

By place

Byzantine Empire

• August 26 - Battle of Manzikert: The Byzantine army under Emperor Romanos IV meets the Seljuk Turk forces of Sultan Alp Arslan near the town of Manzikert. Although the armies are initially evenly matched, as the Byzantines advance the Seljuk Turks withdraw before them, launching hit-and-run attacks on the Byzantine flanks. While attempt to withdraw the Byzantine army falls apart, either through treachery or confusion – the battle ends in a decisive defeat for the Byzantine Empire. Romanos is captured and much of the elite Varangian Guard is destroyed.
• October 24 - Romanos IV is deposed by Caesar John Doukas and his political advisor Michael Psellos. Michael VII is crowned co-emperor – and his mother Eudokia is forced to retire to a monastery.

  Europe

• February 22 - Battle of Cassel: Robert I defeats his sister-in-law Richilde and her nephew Arnulf III, in a succession struggle for the County of Flanders. Robert is appointed count by King Philip I.
• April 15 - Siege of Bari: The capital of Bari, the last Byzantine-controlled city in the Catepanate of Italy, is captured by Italo-Norman forces under Duke Robert Guiscard after a 32-month siege.

  England

• The English rebels under Hereward and Morcar, Saxon former earl of Northumbria, are forced to retreat to their stronghold on the Isle of Ely. They make a desperate stand against the Norman forces led by King William I, but are defeated.
• Edwin, earl of Mercia, rebels against William I, but is betrayed and killed. His castle and lands at Dudley are given to William's Norman subjects.

  Africa

• May - Zaynab an-Nafzawiyyah marries Yusuf ibn Tashfin, leader of the Almoravids, and becomes his queen and co-regent.