Capital of the Turkish empire, on the Bosphorus, situated on a peninsula washed by the Sea of Marmora on the S. and by the Golden Horn on the N., on the opposite side of which creek lie the quarters of Galata and Pera, one of the finest commercial sites in the world; it became the capital of the Roman empire under Constantine the Great, who gave name to it; was capital of the Eastern empire from the days of Theodosius; was taken by the crusaders in 1204, and by Mahomet II. in 1452, at which time the Greek and Latin scholars fled the city, carrying the learning of Greece and Rome with them, an event which led to the revival of learning in Europe, and the establishment of a new era—the Modern—in European history.