section_path: Legacy/Political aftermath
section_name: Political aftermath
paragraph_text: Political aftermath
  
  By the time of the fall of Constantinople, the Byzantine Empire, already an empire in name only since the Fourth Crusade, had been reduced to three rump states: the Despotate of the Morea, the Empire of Trebizond and the Principality of Theodoro. The Morea was ruled by the brothers of Constantine XI, Thomas Palaiologos and Demetrios Palaiologos. The despotate continued as an independent state by paying an annual tribute to the Ottomans. Incompetent rule, failure to pay the annual tribute, and a revolt against the Ottomans finally led to Mehmed II's invasion of Morea in May 1460.
  
  A few holdouts remained for a time. In the Morea, the island of Monemvasia came under the pope's protection before the end of 1460, while the Mani Peninsula submitted to Venice. The Empire of Trebizond, which had split away from the Byzantine Empire just weeks before Constantinople was taken by the Crusaders in 1204, became the last remnant of and de facto successor state to the Byzantine Empire. Efforts by Emperor David to recruit European powers for an anti-Ottoman crusade provoked war between the Ottomans and Trebizond in the summer of 1461. After a month-long siege, David surrendered the city of Trebizond on 14 August 1461. Trebizond's Crimean principality, the Principality of Theodoro (part of the Perateia), lasted another 14 years, falling to the Ottomans in December 1475.
  
  Mehmed II and his successors continued to consider themselves heirs to the Roman Empire. They considered that they had shifted their religious basis as Constantine had done before, and they continued to refer to their conquered Eastern Roman inhabitants (Orthodox Christians) as Rûm. This claim gradually faded away as the Ottoman Empire assumed a more Islamic political identity. Meanwhile, the Danubian Principalities (whose rulers also considered themselves the heirs of the Eastern Roman Emperors) harboured Orthodox refugees, including some Byzantine nobles.
  
  At Constantine's death, the role of the emperor as a patron of Eastern Orthodoxy was claimed by Ivan III, Grand Prince of Muscovy. He had married Andreas' sister, Sophia Palaiologina, whose grandson, Ivan IV, would become the first tsar of Russia (tsar, or czar, meaning caesar, is a term traditionally applied by Slavs to the Byzantine emperors). Their successors supported the idea that Moscow was the proper heir to Rome and Constantinople. The idea of the Russian Empire as the successive Third Rome was kept alive until its demise with the Russian Revolution.