The barrier of religion would have kept the Latins and Greeks asunder, even if differences of nationality and civilisation had not proved effective causes of separation. Despite the rejoicings of Innocent III., Orthodox and Catholic were more divided than ever, when the Filioque was chanted by azymites in the choir of St. Sophia, and beardless Latins, who regarded the Pope as the source of all ecclesiastical power, took into their hands every Church dignity and possession, and branded their rightful owners as schismatics. Orthodoxy and the pressure of the Latin invaders united Greek national feeling as it had never been united before. In the mountains of Albania and Epirus, the bolder Greeks fled from the yoke of the conqueror, and maintained their independence against any force that the Latins could bring to bear against them. A bastard of the house of Angelus became Despot of Epirus. Even in Thrace and in the Peloponnesus there were independent Greek States. Into Asia the Crusaders hardly penetrated at all. Two brothers of the house of Comnenus established the independence of distant Trebizond, and dignified themselves, like Isaac in Cyprus, with the title of Emperor. [Sidenote: Theodore I. Lascaris, 1204–1222.] Theodore Lascaris, a brave soldier who escaped from the sack of Constantinople, proclaimed himself Emperor at Nicæa, and ruled over the western parts of Asia Minor. It was well for Greeks and Latins alike that the dissension and decay of the Seljukians of Roum, and the pressure of Tartar invasion, deprived Islam of its power of aggression. In Europe the Wallachio-Bulgarian kingdom easily maintained its independence and enlarged its boundaries at the expense of the crusading state. Nothing but the secure possession of the great military position of Constantinople, and the command of the sea, which the Venetian galleys still kept open for them, allowed the Latin Empire to keep up a feeble existence for nearly sixty years. [Sidenote: Rivalry of Constantinople and Thessalonica.]