Military history of the Crusader states
The Seljuk–Crusader War began when the First Crusade wrested territory from the Seljuk Turks during the Siege of Nicaea in 1097 and lasted until 1128 when Zengi became atabeg of Aleppo. At the latter date, the chief threat to the Crusaders from the east and north became the Zengids. The conflict was generally fought between European Crusaders and the Seljuk Turks and their vassals. The Muslim Syrian emirates occasionally allied themselves with the Christians against rival states.
History of antisemitism
The Crusades were a series of military campaigns sanctioned by the Papacy in Rome, which took place from the end of the 11th century until the 13th century. They began as endeavors to recapture Jerusalem from the Muslims but developed into territorial wars.