The Latin Empire was a feudal Crusader state founded by the leaders of the Fourth Crusade on lands captured from the Byzantine Empire. The Latin Empire was intended to replace the Byzantine Empire as the Western-recognized Roman Empire in the east, with a Catholic emperor enthroned in place of the Eastern Orthodox Roman emperors.

The Fourth Crusade had originally been called to retake the Muslim-controlled city of Jerusalem, but a sequence of economic and political events culminated in the Crusader army sacking the city of Constantinople, the capital of the Byzantine Empire. Originally, the plan had been to restore the deposed Byzantine Emperor Isaac II Angelos, who had been usurped by Alexios III Angelos, to the throne. The crusaders had been promised financial and military aid by Isaac's son Alexios IV, with which they had planned to continue to Jerusalem. When the crusaders reached Constantinople the situation quickly turned volatile and while Isaac and Alexios briefly ruled, the crusaders did not receive the payment they had hoped for. In April 1204, they captured and plundered the city's enormous wealth.

The crusaders selected their own emperor from among their own ranks, Baldwin of Flanders, and divided the territory of the Byzantine Empire into various new vassal crusader states. The Latin Empire's authority was immediately challenged by Byzantine rump states led by the Laskaris family (connected to the Angelos dynasty of 1185–1204) in Nicaea and the Komnenos family (which had ruled as Byzantine Emperors 1081–1185) in Trebizond. From 1224 to 1242 the Komnenos Doukas family, also connected to the Angeloi, challenged Latin authority from Thessalonica. The Latin Empire failed to attain political or economic dominance over the other Latin powers that had been established in former Byzantine territories in the wake of the Fourth Crusade, especially Republic of Venice, and after a short initial period of military successes it went into a steady decline due to constant war with Bulgaria to the north and the various Byzantine claimants. Eventually, the Nicene Empire recovered Constantinople and restored the Byzantine Empire under Michael VIII Palaiologos in 1261. The last Latin emperor, Baldwin II, went into exile, but the imperial title survived, with several pretenders to it, until the 14th century.