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 communities in the Balkans, Caucasus, Crimea, and Volga region. The term "Muslim Europe" is used to refer to the Muslim-majority countries in the Balkans (Albania, Bosnia and Herzegovina, 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 indigenous European Muslims, although the majority are secular.
Islam expanded into the Caucasus through the Muslim conquest of Persia in the 7th century and entered Southern Europe after the Umayyad conquest of Hispania in the 8th–10th centuries; Muslim political entities existed firmly in what is today Spain, Portugal, Sicily, and Malta during the Middle Ages. The Muslim populations in these territories were either converted to Christianity or expelled by the end of the 15th century by the indigenous Christian rulers (see Reconquista). The Ottoman Empire further expanded into Southeastern Europe and consolidated its political power by invading and conquering huge portions of the Serbian Empire, Bulgarian Empire, and the remaining territories of the Byzantine Empire in the 14th and 15th centuries. Over the centuries, the Ottoman Empire gradually lost almost all of its European territories, until it was defeated and eventually collapsed in 1922. Islam spread in Eastern Europe via the conversion of the Volga Bulgars, Cuman-Kipchaks, and later the Golden Horde and its successor khanates, with its various Muslim populations called "Tatars" by the Russians. Historically significant Muslim populations in Europe include the Gorani, Torbeshi, Pomaks, Bosniaks, Muslim Albanians, Cham Albanians, Greek Muslims, Vallahades, Muslim Romani people, Balkan Turks, Turkish Cypriots, Cretan Turks, Yörüks, Volga Tatars, Crimean Tatars, Kazakhs, Gajals, and Megleno-Romanians.
In the late 20th and early 21st centuries, large numbers of Muslims immigrated to Western Europe. By 2010, an estimated 44 million Muslims were living in Europe (6%), including an estimated 19 million in the EU (3.8%). They are projected to compose 8% or 58 million by 2030. Islam in Europe is often the subject of intense discussion and political controversies sparked by events such as Islamic terrorist attacks in European countries, The Satanic Verses controversy, the cartoons affair in Denmark, debates over Islamic dress, and growing support for right-wing populist movements and parties that view Muslims as a threat to indigenous European culture and liberal values. Such events have also fueled ongoing debates regarding the topics of globalization, multiculturalism, nativism Islamophobia, relations between Muslims and other religious groups, and populist politics.
History
The Muslim population in Europe is extremely diverse with varied histories and origins. Today, the Muslim-majority regions of Europe are the Balkans (Albania, Bosnia and Herzegovina, Kosovo, and the European part of Turkey), some Russian republics in the North Caucasus and the Idel-Ural region, and the European part of Kazakhstan. These communities consist predominantly of indigenous Europeans of the Muslim faith, whose religious tradition dates back several hundred years to the Middle Ages. The transcontinental countries of Turkey, Azerbaijan, and Kazakhstan are also majority Muslim.
Western Europe and the Mediterranean Region
Arab Muslim forays into Europe began shortly after the foundation of Islam in the 7th century CE. Soon after the death of Muhammad in 632 CE, his community needed to appoint a new leader, giving rise to the title of caliph (), which was claimed by some of Muhammad's closest companions (ṣaḥāba) and their descendants over the succession for the role of caliph throughout the centuries. The four "rightly-guided" (rāshidūn) caliphs who succeeded him oversaw the initial phase of the early Muslim conquests, advancing through Persia, the Levant, Egypt, and North Africa.