By the 1450s, the Ottoman Empire either occupied or had established hegemony over much of the territories the Byzantine Empire held before the Fourth Crusade sacked Constantinople in 1204. Many of Mehmed's campaigns in that period can be explained by assuming he was taking possession of the bits and fragments that he still did not rule directly: Enos fell after a lightning march in the winter of 1456;[8] after showing unusual patience with the surviving Palaiologoi ruling the Morea, who spent more time fighting each other than paying their tribute, Mehmed at last conquered all but one Byzantine fortress in that peninsula when Mistra fell on 29 May 1460;[9] Amasria was taken from the Genoese around the same time;[10] except for several islands in the Aegean Sea under the rule of various Latin lords, Trebizond was the one remaining piece of the former Eastern Roman Empire not under Mehmed's direct rule.[11]