The Kingdom of Jerusalem, officially known as the Latin Kingdom of Jerusalem, also known as the Frankish Kingdom of Jerusalem, was a Crusader state that was established in the Levant immediately after the First Crusade. It lasted for almost two hundred years, from the accession of Godfrey of Bouillon in 1099 until the siege of Acre in 1291. Its history is divided into two periods with a brief interruption in its existence, beginning with its collapse after the siege of Jerusalem in 1187 and its restoration after the Third Crusade in 1192.

The original Kingdom of Jerusalem lasted from 1099 to 1187 before being almost entirely overrun by the Ayyubid Sultanate under Saladin. Following the Third Crusade, it was re-established in Acre in 1192. The re-established state is commonly known as the "Second Kingdom of Jerusalem" or alternatively as the "Kingdom of Acre" after its new capital city. Acre remained the capital for the rest of its existence excluding the two decades that followed the Crusaders' establishment of partial control over Jerusalem during the Sixth Crusade, through the diplomacy of Frederick II of Hohenstaufen vis-à-vis the Ayyubids.

The vast majority of the Crusaders who established and settled the Kingdom of Jerusalem were from the Kingdom of France, as were the knights and soldiers who made up the bulk of the steady flow of reinforcements throughout the two-hundred-year span of its existence; its rulers and elite were therefore predominantly French. French Crusaders also brought their language to the Levant, thus establishing Old French as the lingua franca of the Crusader states, in which Latin served as the official language. While the majority of the population in the countryside comprised Christians and Muslims from local Levantine ethnicities, many Europeans (primarily French and Italian) also arrived to settle in villages across the region.