Constantinople was besieged thirty-four times throughout its history. Out of the ten sieges that occurred during its time as a city-state and while it was under Roman rule, six were successful, three were repelled and one was lifted as a result of the agreement between the parties. Three of these sieges were carried out by the Romans who claimed the throne during civil war. Of the twenty-four sieges that took place while it was under Byzantine rule, five were successful, fourteen remained inconclusive, and five were lifted by reaching mutual agreements. Four of these sieges took place during civil wars. The Sack of Constantinople that that took place in 1204 during the Fourth Crusade caused the city to fall and established the Latin Empire. It also sent the Byzantine imperial dynasty to exile, who founded the Empire of Nicaea. Constantinople came under Byzantine rule again in 1261, but was conquered by the Ottomans with the siege in 1453, as a result of which the Byzantine Empire came to an end. The city has been under the rule of Turks since the last siege, except for the period of Allied occupation from 1920 to 1923.