The Balkan people, ruled long as Turkish subjects, have gradually formed themselves into five principal groups as follows: the Serbians, dwelling in the interior of the country northwest of Turkey proper and occupying much of the hinterland lying east of the Adriatic; the Bulgars, settled east of the Serbs and extending as far as the shores of the Black Sea; the Wallachians and Moldavians, who were of kindred stock and became known as Rumanians because they believed themselves the descendants of the inhabitants of the ancient Roman colony of Dacia; the Albanians living along the lower eastern shores of the Adriatic; and the Montenegrins, of the same race as the Serbians, who defended themselves so well in their mountain strongholds that they could say they had never been conquered by the Turks. Many race elements entered into these groups, but the Serbs and Montenegrins were largely Slavic, while the Bulgars were generally of a distinct race of Asiatic origin, and the Rumanians were generally Vlachs, a name given to the Latin speaking population of the Eastern Roman Empire. The Albanians seem to be of mixed stock, but they have a strong sense of nationality. These five groups correspond respectively to the five civil divisions that have emerged from the Turkish provinces, each playing its part in the modern Balkan problem. Montenegro aside, the first group to become a state was Serbia, whose hardy mountain inhabitants rose in revolt in 1804. A number of brave leaders appeared and valley by valley the Turks were forced out of the country. The Serbs were practically independent for a time, but the sultan did not acquiesce in their freedom, and the constant preparedness that was necessary to repel any attack he might launch was a source of much expense and anxiety to the people.