1. This country was founded by nomad immigrants from the Russian steppes in the 6th century, on lands that were part of the Byzantine Empire. Although it was conquered by Emperor Basil II in 1018, a revolt reestablished its independence in 1185, and it came to rule much of the southern Balkans. It was conquered again by the Turks in 1396, and remained subject to them until 1908. FTP, name this European country, the last to enter World War I on the side of the Central Powers.