1090

• 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.Gilbert Meynier (2010). L'Algérie cœur du Maghreb classique. De l'ouverture islamo-arabe au repli (658-1518). Paris: La Découverte; p. 83.
• King Stephen II of Croatia becomes involved in an open conflict between factions of the Croatian nobility, who reassert their traditional rights in their own counties.

• 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.Steven Runciman (1952). A History of the Crusades. Vol II: The Kingdom of Jerusalem, pp. 96–97. {{ISBN|978-0-241-29876-3}}.

• Béjaïa (or Bugia) becomes the capital of the Hammadid dynasty in modern-day Algeria. It becomes an important port and centre of culture.

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

• 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.

• January 17 – Qin Hui, Chinese chancellor (d. 1155)
• unknown dates
• Frederick II ("the One-Eyed"), German nobleman (d. 1147){{cite book|author=John B. Freed|title=Frederick Barbarossa: The Prince and the Myth|url=https://books.google.com/books?id=tng8DAAAQBAJ&pg=PR19|date=1 January 2016|publisher=Yale University Press|isbn=978-0-300-12276-3|pages=19}}
• Dōin (Fujiwara no Atsuyori), Japanese waka poet (d. 1179)McMillan, Peter. 2010 (1st ed. 2008). One Hundred Poets, One Poem Each. New York: Columbia University Press. Page 146
• probable
• Adolf III, German count of Berg and Hövel (d. 1152)
• 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, Duke of Zähringen, German nobleman and rector of Burgundy (d. 1152)
• Niklot (or Nyklot), Obotrite prince and tribal chief (d. 1160)
• Robert, 1st Earl of Gloucester, illegitimate son of King Henry I of England
• Theobald II, Count of Champagne ("the Great"), French nobleman
• Theobald of Bec, Norman churchman, archbishop of Canterbury
• William de Mohun, 1st Earl of Somerset, Anglo-Norman nobleman

• 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{{cite book|title=Eleventh-century Germany: The Swabian chronicles|url=https://books.google.com/books?id=PW8CEAAAQBAJ&pg=PA299|date=1 January 2013|publisher=Manchester University Press|isbn=978-1-5261-1282-8|pages=299}}
• 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){{cite book |last = Kanō |first = higefumi

|author-link = Shigefumi Kanō |chapter =Fujiwara no Atsuie |script-chapter = ja:藤原敦家 |pages = 267 |title = Nihon Koten Bungaku Daijiten |script-title = ja:日本古典文学大辞典 |language = Japanese |year = 1983 |volume = 5 |location = Tokyo |publisher = Iwanami Shoten |oclc = 11917421}}

• 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 painterBarnhart, R. M. et al. (1997). Three thousand years of Chinese painting. New Haven, Yale University Press. {{ISBN|0-300-07013-6}} Page 372
• St Isaiah of Rostov, Kievan missionary and bishop{{cite book|author1=Alban Butler|author2=Paul Burns|title=Butler's Lives of the Saints|url=https://books.google.com/books?id=7f1CnVuWceQC&pg=PA84|date=1 January 1997|publisher=A&C Black|isbn=978-0-86012-254-8|pages=84}}
• Raynald I, French Benedictine abbot (b. 1059)
• William of Poitiers, French priest and chronicler (b. c.1020)
• probable
• Osbern of Canterbury, English hagiographer

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