Islam in Kosovo has a long-standing tradition dating back to the Ottoman conquest of the Balkans, including Kosovo. Before the Battle of Kosovo in 1389, the entire Balkan region had been Christianized by both the Western and Eastern Roman Empire. From 1389 until 1912, Kosovo was officially governed by the Muslim Ottoman Empire and, as such, a high level of Islamization occurred. During the time period after World War II, Kosovo was ruled by secular socialist authorities in the Socialist Federal Republic of Yugoslavia (SFRY). During that period, Kosovars became increasingly secularized. Today, 93% of Kosovo's population are from Muslim family backgrounds, most of whom are ethnic Albanians. There are also Slavic speaking Muslims, who define themselves as Bosniaks and Gorani, and Turks.