The timeline of the Kingdom of Jerusalem presents important events in the history of the Kingdom of Jerusalem—a Crusader state in modern day Israel and Jordan—in chronological order. The kingdom was established after the First Crusade in 1099. Its first ruler Godfrey of Bouillon did not take the title of king and swore fealty to the Latin Patriarch of Jerusalem, Daimbert. Godfrey's brother and successor Baldwin I was crowned the first king of Jerusalem without doing homage to the patriarch in 1100. By 1153, Baldwin I and his successors captured all towns on the Palestinian coast with the support of Pisan, Genoese and Venetian fleets and also took control of the caravan routes between Egypt and Syria. The kings regularly administered other crusader states—the Counties of Edessa and Tripoli and the Principality of Antioch—on behalf of their absent or underage rulers.
The polarisation of the Muslim world enabled the crusaders (colloquially known as Franks in the Levant) to consolidate their rule in Palestine. They could also appeal to the popes and the European rulers for help against their enemies. In the mid-twelfth century, Baldwin III and his successor Amalric maintained a close alliance with the Byzantine Empire, but they could not prevent the ruler of Aleppo, Nur ad-Din, from uniting the Muslim states in Syria in the 1150s. Internal strife weakened the kingdom during the reigns of the leper Baldwin IV and the unpopular Guy of Lusignan. This facilitated Nur ad-Din's former general, Saladin, to unite Egypt and Syria in the 1180s. Saladin annihilated the crusader army in the Battle of Hattin on 4 July 1187, and occupied almost the whole kingdom during the following months.
An Italian crusader, Conrad of Montferrat, saved Tyre and the Third Crusade forced Saladin to acknowledge the restoration of the Franks' rule in most coastal towns in his 1192 truce with Richard I of England. Further lands were recovered during the reigns of Henry of Champagne and Aimery of Lusignan, and Frederick II, Holy Roman Emperor, also restored the Franks' rule in Jerusalem in 1229. Frederick and his successors were absent monarchs and the kingdom was administered by regents (or bailiffs) from 1229 to 1269. Due to conflicts between the kings' representatives and the powerful barons, and the War of Saint Sabas between Genoa and Venice, the kingdom disintegrated into autonomous towns and lordships by the 1260s. The personal union of Jerusalem and Cyprus could not prevent the Mamluks of Egypt from occupying the last Frankish outposts in 1291. In addition to the Lusignan kings of Cyprus, the Angevin rulers of Naples and their successors maintained a claim to the defunct Jerusalemite kingdom for centuries.