The people who are today called "Macedonians" are descendants of Slavic tribes who settled in Macedonia during the sixth and seventh centuries A.D. They were called "Sclavini" by the Byzantines, and they were looked upon as uncouth barbarians. Late in the seventh century, the Proto-Bulgarians crossed the Danube and came into contact with the "Sclavini." Out of the mixture of the two peoples emerged the Bulgarians, who eventually established a state that included a large part of Macedonia. During the ninth century, two Greek brothers from Thessaloniki (Salonika), Cyril and Methodius, were instrumental in the conversion of the Slavs to Christianity. They were also responsible for the creation of an alphabet, the Glagolitic, out of which evolved the Cyrillic. By the end of the tenth century, there existed two Bulgarian Kingdoms. The kingdom in the west had its capital in Ohrid and covered much of Macedonia. The claims of certain Yugoslav historians that the Western Bulgarian Kingdom was the first Macedonian state have been proven erroneous. On the contrary, evidence suggests that at that time there did not yet exist a "Macedonian" consciousness and that the Slavs of Macedonia regarded themselves as Bulgarians. In any case, the Western Bulgarian Kingdom lasted only a few years until its conquest by the Byzantines. It was not until a couple of centuries later that the second Bulgarian state was able to emerge, only to be swallowed up by an expanding Serbian kingdom, which soon fell under Ottoman control, lasting until 1912. In 1870 the Ottomans aided in the creation of a Bulgarian Orthodox church, which established its Independence from the patriarchate of Constantinople. It was at about this time that a movement was begun in Macedonia by the Slavs to join Macedonia to an independent Bulgarian state, which finally happened in 1878. The union lasted only a few months and Macedonia fell once again under Turkish control. Terrorist organizations, armed and guided by Bulgarians, agitated for liberation from the Turks. With the defeat of the Turks in the Balkan Wars (1912, 1913), Macedonia was divided between Greece, Serbia, and Bulgaria. By the 1920s, with the exchange of populations between the Balkan states, almost all the Slavs had crossed into either Bulgaria or Serbia. It was at about that time that the Comintern (the Communist International) called for the creation of an independent Macedonia and the recognition of a "Macedonian" nationality. A sentiment of separateness had developed among the Slavs of Macedonia during the previous decades. Although they still viewed themselves as Bulgarians, they now emphasized their regional identity as "Macedonians." In this struggle for a new identity they were aided by the Communist parties in Bulgaria, Greece, and Yugoslavia. When Communists came into power in Yugoslavia, Macedonia became a province, or socialist republic, of the Yugoslav federation. The Slavs of Macedonia were then used by Tito as tools in his expansionist policy, which envisioned the creation of a "Greater Macedonia" to include Greek Macedonia and thus to gain access to the Aegean Sea. It should be noted that there is no connection between the Macedonians of the time of Alexander the Great, who were related to other Hellenic tribes, and the Macedonians of today, who are of Slavic origin and related to the Bulgarians. As a result of the region's turbulent history, the "Macedonian question" is the source of great tension in the central Balkan region.