There are accounts of the trade connections between the Muslims and the Rus, apparently people from Baltic region who made their way towards the Black Sea through Central Russia. On his way to Volga Bulgaria, Ibn Fadlan brought detailed reports of the Rus, claiming that some had converted to Islam. "They are very fond of pork and many of them who have assumed the path of Islam miss it very much." The Rus also relished their nabidh, a fermented drink Ibn Fadlan often mentioned as part of their daily fare.
The Mongols began their conquest of Rus', Volga Bulgaria, and the Cuman-Kipchak Confederation (present day Russia and Ukraine) in the 13th century. After the Mongol empire split, the eastern European section became known as the Golden Horde. Despite the fact that they were not Muslim at the time, the western Mongols adopted Islam as their religion in the early 14th century under Berke Khan, and later Uzbeg Khan who established it as the official religion of the state. Much of the mostly Turkic-speaking population of the Horde, as well as the small Mongol aristocracy, were Islamized (if they were not already Muslim, such as the Volga Bulgars) and became known to Russians and Europeans as the Tatars. More than half of the European portion of what is now Russia and Ukraine, were under suzerainty of Muslim Tatars and Turks from the 13th to 15th centuries. The Crimean Khanatebecame a vassal state of the Ottoman Empire in 1475 and subjugated what remained of the Great Horde by 1502. The Khanate of Kazan was conquered by Ivan the Terrible in 1552.
Medieval Bulgaria particularly the city of Sofia, was the administrative centre of almost all Ottoman possessions in the Balkans also known as Rumelia.
The Ottoman Empire began its expansion into Europe by taking the European portions of the Byzantine Empire in the 14th and 15th centuries up until the 1453 capture of Constantinople, establishing Islam as the state religion in the region. The Ottoman Empire continued to stretch northwards, taking Hungary in the 16th century, and reaching as far north as the Podolia in the mid-17th century (Peace of Buczacz), by which time most of the Balkans was under Ottoman control. Ottoman expansion in Europe ended with their defeat in the Great Turkish War. In the Treaty of Karlowitz (1699), the Ottoman Empire lost most of its conquests in Central Europe. The Crimean Khanate was later annexed by Russia in 1783. Over the centuries, the Ottoman Empire gradually lost almost all of its European territories, until its collapse in 1922, when the former empire was transformed into the nation of Turkey.
Between 1354 (when the Ottomans crossed into Europe at Gallipolli) and 1526, the Empire had conquered the territory of present day Greece, Bulgaria, Romania, Albania, Serbia, Macedonia, Montenegro, Bosnia and Hungary. The Empire laid siege to Vienna in 1683. The intervention of the Polish King broke the siege, and from then afterwards the Ottomans battled the Habsburg Emperors until 1699, when the Treaty of Karlowitz forced them to surrender Hungary and portions of present day Croatia, Slovenia and Serbia. From 1699 to 1913, wars and insurrections pushed the Ottoman Empire further back until it reached the current European border of present-day Turkey.
For most of this period, the Ottoman retreats were accompanied by Muslim refugees from these province (in almost all cases converts from the previous subject populations), leaving few Muslim inhabitants in Hungary, Croatia, and the Transylvania region of present day Romania. Bulgaria remained under Ottoman rule until around 1878, and currently its population includes about 131,000 Muslims (2001 Census) (see Pomaks).
Bosnia was conquered by the Ottomans in 1463, and a large portion of the population converted to Islam in the first 200 years of Ottoman domination. By the time Austria-Hungary occupied Bosnia in 1878, the Habsburgs had shed the desire to re-Christianize new provinces. As a result, a sizable Muslim population in Bosnia survived into the 20th century. Albania and the Kosovo area remained under Ottoman rule until 1913. Previous to the Ottoman conquest, the northern Albanians were Roman Catholic and the southern Albanians were Christian Orthodox, but by 1913 the majority were Muslim.
Conversion to Islam
Apart from the effect of a lengthy period under Ottoman domination, many of the subject population were converted to Islam as a result of a deliberate move by the Ottomans as part of a policy of ensuring the loyalty of the population against a potential Venetian invasion. However, Islam was spread by force in the areas under the control of the Ottoman Sultan through devşirme and jizya. Rather Arnold explains Islam's spread by quoting 17th-century pro-Muslim author Johannes Scheffler who stated:
Meanwhile he (i.e. the Turk) wins (converts) by craft more than by force, and snatches away Christ by fraud out of the hearts of men. For the Turk, it is true, at the present time compels no country by violence to apostatise; but he uses other means whereby imperceptibly he roots out Christianity... What then has become of the Christians? They are not expelled from the country, neither are they forced to embrace the Turkish faith: then they must of themselves have been converted into Turks.
Iberia and Southern France
A manuscript page of the Qur'an in the script developed in al-Andalus, 12th century.
Muslim forays into Europe began shortly after the religion's inception, with a short lived invasion of Byzantine Sicily by a small Arab and Berber forcethat landed in 652. Islam gained its first foothold in continental Europe from 711 onward, with the Umayyad conquest of Hispania. The invaders named their land Al-Andalus, which expanded to include what is now Portugal and Spain except for the northern highlands of Asturias, Basque country, Navarra and few other places protected by mountain chains from southward invasions.
The local population conquered by the Muslims were Romanized Catholic Sicilians in Western Sicily and partially Greek speaking Christians, mainly in the eastern half of the island, but there were also a significant number of Jews.These conquered people were afforded a limited freedom of religion under the Muslims as dhimmi, but were subject to some restrictions. The dhimmi were also required to pay the jizya, or poll tax, and the kharaj or land tax, but were exempt from the tax that Muslims had to pay (Zakaat). Under Arab rule there were different categories of Jizya payers, but their common denominator was the payment of the Jizya as a mark of subjection to Muslim rule in exchange for protection against foreign and internal aggression. The conquered population could avoid this subservient status simply by converting to Islam. Whether by honest religious conviction or societal compulsion large numbers of native Sicilians converted to Islam. However, even after 100 years of Islamic rule, numerous Greek speaking Christian communities prospered, especially in north-eastern Sicily, as dhimmi. This was largely a result of the Jizya system which allowed co-existence. This co-existence with the conquered population fell apart after the reconquest of Sicily, particularly following the death of King William II of Sicily in 1189.
Cultural impact and Christian interaction
"Araz" coat of arms of Polish Tatar nobility. Tatar coats of arms often included motifs related to Islam.
Islam piqued interest among European scholars, setting off the movement of Orientalism. The founder of modern Islamic studies in Europe was Ignác Goldziher, who began studying Islam in the late 19th century. For instance, Sir Richard Francis Burton, 19th-century English explorer, scholar, and orientalist, and translator of The Book of One Thousand and One Nights, disguised himself as a Pashtun and visited both Medina and Mecca during the Hajj, as described in his book A Personal Narrative of a Pilgrimage to Al-Medinah and Meccah.
According to the Pew Forum, the total number of Muslims in Europe in 2010 was about 44 million (6%), excluding Turkey. The total number of Muslims in the European Union in 2010 was about 19 million (3.8%). Approximately 9 million Turks are living in Europe, excluding the Turkish population of Turkey, which makes up the largest Muslim immigrant community in Europe. However the real number of Muslims in Europe is not well-known. The percentage of Muslims in Russia(the biggest group of Muslims in Europe) varies from 5 to 11.7%,depending on sources. It also depends on if only observant Muslims or all people of Muslim descent are counted.
The UN High Commissioner for Refugees estimated that 70% of the people of Albania  are Muslim, 91% in Kosovo, and 30% of them in Macedonia are Muslim. Bosnia has a Muslim plurality. In transcontinental countries such as Turkey 99%, and 93% in Azerbaijan of the population is Muslim respectively. Muslims also form about one sixth of the population of Montenegro. In Russia, Moscow is home to an estimated 1.5 million Muslims.
According to the Pew Research Center, Europe's population was 6% Muslim in 2010, and is projected to be 8% Muslim by 2030.
Don Melvin wrote in 2004 that, excluding Russia, Europe's Muslim population will double by 2020. He also says that almost 85% of Europe's total population growth in 2005 was due to immigration in general. Omer Taspinar predicted in 2001 that the Muslim population of Europe will nearly double by 2015, while the non-Muslim will shrink by 3.5%, if the higher Muslim birth rate persists. In the UK, between 2001 and 2009, the Muslim population increased roughly 10 times faster than the rest of the population.
A 2007 Center for Strategic and International Studies (CSIS) report argued that some Muslim population projections are overestimated.Philip Jenkins of Penn State University estimates that by 2100, Muslims will compose about 25% of Europe's population. Jenkins states this figure does not take account divergent birthrates amongst Europe's immigrant Christians. Other analysts are skeptical about the accuracy of the claimed Muslim population growth, stating that because many European countries do not ask a person's religion on official forms or in censuses, it has been difficult to obtain accurate estimates, and arguing that there has been a decrease in Muslim fertility rates in Morocco, the Netherlands and Turkey. A Pew Research Centerstudy, published in January 2011, forecast an increase of Muslims in European population from 6% in 2010 to 8% in 2030. Pew also found that Muslim fertility rate in Europe would drop from 2.2 in 2010 to 2.0 in 2030. On the other hand, the non-Muslim fertility rate in Europe would increase from 1.5 in 2010 to 1.6 in 2030.