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Events

Spring – Seljuk forces led by Imad al-Din Zengi capture Saruj, the second great Crusader fortress east of the Euphrates. They advance to Birejik and besiege the city, but the garrison puts up a stiff resistance. Meanwhile, Queen-Regent Melisende of Jerusalem joins forces with Joscelin II, count of Edessa and approaches the city. Zengi raises the siege after hearing rumours of trouble in Mosul. He rushes back with his army to take control. There, Zengi is praised throughout Islam as "defender of the faith" and al-Malik al-Mansur, the "victorious king".<ref>Steven Runciman (1952). A History of The Crusades. Vol II: The Kingdom of Jerusalem, p. 192. Template:ISBN.</ref>
Raymond of Poitiers, prince of Antioch, travels to Constantinople to ask Emperor Manuel I Komnenos for help to support his campaign against the Seljuks. When he arrives, Raymond is forced to accept the suzerainty of the Byzantine Empire. Manuel treats him graciously, gives him gifts and promises him a money subsidy.<ref>Steven Runciman (1952). A History of The Crusades. Vol II: The Kingdom of Jerusalem, p. 193. Template:ISBN.</ref>

Spring – Arnold of Brescia, an Italian priest from Lombardy, turns Rome into a republic with a government patterned on that of the Roman Republic. Arnold becomes the intellectual leader of the Commune of Rome, calling for liberties and democratic rights after the deposition of Giordano Pierleoni.

Spring – Almohad forces under Abd al-Mu'min defeat a Muslim Almoravid army at Tlemcen.<ref name=Maghrebclassique /> Almoravid ruler Tashfin ibn Ali dies while escaping his enemies near Oran. He is succeeded by his son Ibrahim ibn Tashfin.
The Merinids of Maghrib al-Aqsa attempt to resist the Almohads but are forced into the desert areas around the Tafilalt.<ref name=Maghrebclassique>Template:Cite book</ref> Oran falls to the Almohads.<ref>Picard C. (1997) La mer et les musulmans d'Occident au Moyen Âge. Paris: Presses universitaires de France, p. 64</ref> A Norman raid against the Tripolitania region succeeds.

Estimation: Merv (in the Seljuk Empire) becomes the largest city in the world, surpassing Constantinople.<ref>Template:Cite web</ref>

Kim Pusik and his team of historians finish the compilation of the Korean historical text Samguk Sagi.
Construction begins on Notre-Dame de Chartres Cathedral in Chartres, France.

February 15 – Pope Lucius II dies at Rome after having been hit by a stone missile during the fighting against Senatorial forces led by Giordano Pierleoni. He is succeeded after an 11-month pontificate by Eugene III who becomes the 167th pope of the Catholic Church. Eugene is forced into exile by Arnold of Brescia.
Woburn Abbey is founded by the Cistercians in England. A colony of monks arrive from Fountains Abbey to establish a community that will survive until 1234.
December 1 – Eugene III issues the bull Quantum praedecessores, calling for the Second Crusade. At Christmas, King Louis VII announces his intention of making a pilgrimage which becomes part of the Crusade.