<P> At his death, the role of the emperor as a patron of Eastern Orthodoxy was claimed by Ivan III, Grand Duke of Muscovy . He had married Andreas' sister, Sophia Paleologue, 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 new, Third Rome was kept alive until its demise with the Russian Revolution of 1917 . </P> <Ol> <Li> Jump up ^ The first instance of the designation "New Rome" in an official document is found in the canons of the First Council of Constantinople (381), where it is used to justify the claim that the patriarchal seat of Constantinople is second only to that of Rome . </Li> </Ol> <Li> Jump up ^ The first instance of the designation "New Rome" in an official document is found in the canons of the First Council of Constantinople (381), where it is used to justify the claim that the patriarchal seat of Constantinople is second only to that of Rome . </Li>

Which of these emerged in the eastern empire following the foundation of constantinople