linguistic:translation, linguistic:paraphrasing
The Crusader states, or Outremer, were four Catholic polities that existed in the Levant from 1098 to 1291. Following the principles of feudalism, the foundation for these polities was laid by the First Crusade, which was proclaimed by the Latin Church in 1095 in order to reclaim the Holy Land after it was lost to the 7th-century Muslim conquest. Situated on the Eastern Mediterranean, the four states were, in order from north to south: the County of Edessa (1098 – 1150), the Principality of Antioch (1098 – 1268), the County of Tripoli (1102 – 1289), and the Kingdom of Jerusalem (1099 – 1291).

The three northern states covered an area in what is now southeastern Turkey, northwestern Syria, and northern Lebanon; and the Kingdom of Jerusalem, the southernmost and most prominent state, covered an area in what is now Israel, Palestine, southern Lebanon, and western Jordan. The description "Crusader states" can be misleading, as from 1130 onwards, very few people among the Franks were Crusaders. Medieval and modern writers use the term "Outremer" as a synonym, derived from the French word for overseas.

By 1098, the Crusaders' armed pilgrimage to Jerusalem was passing through the Syria region. Edessa, under the rule of Greek Orthodoxy, was subject to a coup d'état in which the leadership was taken over by Baldwin of Boulogne, and Bohemond of Taranto remained as the ruling prince in the captured city of Antioch. The siege of Jerusalem in 1099 resulted in a decisive Crusader victory over the Fatimid Caliphate, after which territorial consolidation followed, including the taking of Tripoli. In 1144, Edessa fell to the Zengid Turks, but the other three realms endured until the final years of the 13th century, when they fell to the Mamluk Sultanate of Egypt. The Mamluks captured Antioch in 1268 and Tripoli in 1289, leaving only the Kingdom of Jerusalem, which had been severely weakened by the Ayyubid Sultanate after the siege of Jerusalem in 1244. The Crusader presence in the Levant collapsed shortly thereafter, when the Mamluks captured Acre in 1291, ending the Kingdom of Jerusalem nearly 200 years after it was founded. With all four of the states defeated and annexed, the survivors fled to the Kingdom of Cyprus, which had been established by the Third Crusade.

The study of the Crusader states in their own right, as opposed to being a sub-topic of the Crusades, began in 19th-century France as an analogy to the French colonial experience in the Levant, though this was rejected by 20th-century historians. Their consensus was that the Frankish population, as the Western Europeans were known at the time, lived as a minority society that was largely urban and isolated from the indigenous Levantine peoples, having separate legal and religious systems. The ancient Jewish communities that had survived and remained in the holy cities of Jerusalem, Tiberias, Hebron, and Safed since the Jewish–Roman wars and the destruction of the Second Temple were heavily persecuted in a pattern of rampant Christian antisemitism accompanying the Crusades.