Battle of Manzikert
A Byzantine defeat opens Anatolia to the Turks

Seljuk sultan Alp Arslan routed the Byzantine army and captured Emperor Romanos IV Diogenes. Turkic settlers then poured into Anatolia, and Byzantium's appeals to the West for help paved the way for the Crusades.
Wikipedia (Russian) · Wikipedia (English) · 11th century
Meanwhile around the world (±25 years)
Europe
- 1066 Battle of Hastings — 5 years earlier
- 1066 Halley's Comet over England — 5 years earlier
- 1077 Walk to Canossa — 6 years later
- c. 1088 University of Bologna — 17 years later
Africa
- c. 1070 The Almoravids found Marrakesh — 1 year earlier
Asia
- 1054 Supernova SN 1054 — 17 years earlier
Alive at the time
- William the Conqueror (aged 43)
- Omar Khayyam (aged 23)
- Henry IV (aged 21)
- Vladimir II Monomakh (aged 18)
- Iziaslav I (aged 47)
- Vsevolod I (aged 41)
- Shen Kuo (aged 40)
- Sviatopolk II (aged 21)
- Philip I (aged 19)
- Nestor the Chronicler (aged 15)