1090

Year 1090 (MXC) was a common year starting on Tuesday (link will display the full calendar) of the Julian calendar.

Europe

 * A third Almoravid expedition is launched in Al-Andalus, designed to finally subdue the Taifa's Kingdoms. The cities of Córdoba, Seville, Granada, Málaga, Almería and Ronda fall to the troops of Sultan Yusuf ibn Tashfin.
 * King Stephen II of Croatia becomes involved in an open conflict between factions of Croatian nobles, who reassert their traditional rights in their own counties.

Seljuk Empire

 * Hassan-i Sabbah founds the Nizari Ismaili state after taking control of the Alamut Castle and organising the military group called the Order of Assassins.

Africa

 * Béjaïa (or Bugia) becomes the capital of the Hammadid Dynasty in modern Algeria. It becomes an important port and centre of culture.

Arts and Culture

 * Troubadours begin playing in western Aquitaine (Poitou and Saintonge) and Gascony (approximate date).

Science and Technology

 * Qin Guan, Chinese poet of the Song Dynasty, writes the Can Shu (Book of Sericulture), which describes a silk-reeling machine that has the world's oldest known mechanical belt drive.

Births

 * January 17 – Qin Hui, Chinese chancellor (d. 1155)
 * unknown dates
 * Frederick II (the One-Eyed), German nobleman (d. 1147)
 * Fujiwara no Atsuyori (or Dōin), Japanese waka poet (d. 1179)
 * probable
 * Agnes I, German abbess of Quedlinburg (approximate date)
 * Alaungsithu, Burmese king of the Pagan Dynasty (d. 1167)
 * Arnold of Brescia, Italian canon regular (approximate date)
 * Bernard of Clairvaux, French abbot and theologian (d. 1153)
 * Chen Yuyi, Chinese politician of the Song Dynasty (d. 1138)
 * Eliezer ben Nathan, German rabbi and liturgical poet (d. 1170)
 * Eric II (the Memorable), king of Denmark (approximate date)
 * Fujiwara no Akisuke, Japanese nobleman and poet (d. 1155)
 * Juliane de Fontevrault, illegitimate daughter of King Henry I of England
 * Conrad I, German nobleman and rector of Burgundy (d. 1152)
 * Niklot (or Nyklot), Obotrite prince and tribal chief (d. 1160)
 * Robert FitzRoy, 1st Earl of Gloucester
 * Theobald II (the Great), French nobleman
 * Theobald of Bec, archbishop of Canterbury
 * William de Mohun, 1st Earl of Somerset

Deaths

 * March 22 – García II, king of Galicia and Portugal (b. 1042)
 * April 16 – Sikelgaita, Lombard duchess of Apulia (b. 1040)
 * May 3 – Adelaide of Rheinfelden, queen consort of Hungary
 * May 12 – Liutold of Eppenstein, German nobleman
 * May 18 – Berthold of Rheinfelden, German nobleman
 * June 26 – Jaromír, Bohemian prince and bishop
 * July 3 – Egbert II (or Ekbert), German nobleman
 * August 11 – Fujiwara no Atsuie, Japanese nobleman (b. 1033)
 * August 13 – Constance of Normandy, duchess of Brittany
 * unknown dates
 * Abd al-Jalil ibn Wahbun, Moorish poet and writer
 * Fayun Faxiu, Chinese Chan Buddhist monk (b. 1027)
 * Richard fitz Gilbert, Norman nobleman (b. c.10350
 * Guo Xi, Chinese landscape painter
 * St Isaiah of Rostov, Kievan missionary and bishop
 * Raynald I, French Benedictine abbot (b. 1059)
 * William of Poitiers, French priest and chronicler (b. c.1020)
 * probable
 * Osbern of Canterbury, English hagiographer