Islam is the second-largest religion in Europe after Christianity. Although the majority of Muslim communities in Western Europe formed recently, there are centuries-old Muslim societies in the Balkans, Southeastern Europe, Caucasus, Crimea, and Volga region, such as Slavic Muslims, Muslim populations of Albanians, Greeks, Romani, Balkan Turks, Pomaks, Yörüks, Volga Tatars, and Crimean Tatars. The term "Muslim Europe" is used to refer to the Muslim-majority countries in the Balkans (Bosnia and Herzegovina, Albania, Kosovo) and parts of countries in Eastern Europe with sizable Muslim minorities (Bulgaria, Montenegro, North Macedonia, and some republics of Russia) that constitute large populations of native European Muslims, although the majority are secular.