The Ottoman Empire conquered the Balkans and occupied it for half a millennium. They managed to convert most of the Albanians to Islam, however, all the other nations in the area remained Christian.
What are the causes of the Albanians being predominantly Muslim, while all the other countries in the Balkans predominantly Christian?
Based on what I've found, I would say that it was a combination of factors that all amplified each other. The conquest of Albania was particularly brutal compared to the rest of the region, and was furthermore contested through the revolt of Gjergj Kastrioti Skënderbeu, which lasted from 1443 through 1468. Even by that time, the region of Krujë had developed into one of the more important subaşilik (an Ottoman gubernatorial region) centers in the Balkans. This basically devastated the area, and led to the emigration of thousands of Albanians to the north (there seems to have been a very large émigré population in Naples because of this)1.
Over the next couple of centuries, the remaining Albanian population was further diluted through the immigration of Muslims from elsewhere in the Ottoman empire. This trend of population movement is noted in many of the contemporary writings and also in traditional accounts of the expansion of Islam into the Balkan regions2.
These demographic trends would have amplified each other as areas with large Muslim populations tended to both serve as magnets for further Muslim resettlement and accelerated the pace at which the rest of the population converted to Islam. This makes quite a bit of sense if you compare it to large regional ethnic concentrations in the United States for example, and I would imagine that similar social dynamics would have been at play. This is actually evident in the tax records for the region, in particular records related to the cizye, or tax on non-believers (thank you Ottomans for keeping good tax records). Population studies based on these records seem to confirm these types of concentrations3.
In addition, this link gives a pretty good summary of the literature and is worth a read.
1 Jelavich, Barbara, History of the Balkans: Eighteen and Nineteenth Centuries, p 34-5
2 Norris, H. T., Islam in the Balkans: Religion and Society Between Europe and the Arab World, p 141-5
3 Minkov, Anton, Conversion to Islam in the Balkans: Kisve Bahas ̧petitions and Ottoman Social Life, 1670-1730, p 43-8
Bosnia and Herzegovina is a second largely Muslim state in the Balkans, with most ethnic Bosnians traditionally professing the Muslim faith. However the Bosnian, Serb and Croat populations in this area are densely intertwined historically, aggravating racial tensions in the Bosnian War of 1992-1995.
The Ottoman empire was not (through most of its occupation of the Balkans) a strongly proselytizing empire. For instance, though the Serbian Patriarchate was abolished in 1463 following the death of Patriarch Arsenios II it was re-established by the Ottomans in 1557. This disruption was thus less than 100 years. Further, forced conversions were not generally required of the subject populations in the Empire, rather non-Muslims suffered from additional taxation and the loss of some rights making them second-class citizens.
Your chronology is also exaggerated. Although the bulk of the Balkans was conquered by the Ottomans in the half-century immediately preceding and following the capture of Constantinople in 1453, much of that area had again obtained independence less than 400 years later. Greece obtained independence by 1832; Moldavia and Wallachia were independent by 1821 and 1848 respectively and unified as Romania in 1859. Serbia was abandoned by the Ottomans by 1867.
Update:
Interestingly, the reason for the conversion of the Albanians to Islam remain unclear. What is agreed is that the conversion primarily occurred late in the period of Ottoman rule; Catholic Albanians mostly converted in the 17th century, and the Orthodox Albanians mostly followed in the following century. Primary source documentation is scarce, hindering research efforts to determine causes and motivations. The country itself is today 59% Muslim, 17% Christian, and the rest other.
Albanians are not the only nation in the Balkans to accept Islam. All societies had groups accepting Islam. The difference of the Albanians is that they are the only nation in the Balkans, who managed to have a national identity above religion. Which means that the term Albanian covers all Albanians of Muslim, Orthodox or Catholic faiths.
This is not observed in other countries. This is due to the tradition from the citizenship system in the Ottoman Empire. Officially in the empire, there was not an ethnic system (which was used in almost all Europe), and instead a religious system was used. (Ethnic separation is forbidden by Islam) So there was no use of the term "Turkish". All muslims of the empire, independent of their ethnicity or native language were classified officially under the "Muslim" identity. The term "Turk" was not commonly used, but even if it was used, it was synonymous with Muslim.
Same applied for Christians. All followers of the Greek Orthodox Church, irrespective of them being Greek, Armenian, Bulgarian, Slavic or even Turkish, were classified officially as "Greeks".
From this tradition, the national identities of modern Balkan states are developed in parallel with the religious identities.
Muslim Bulgarians were are not called (and accepted as) Bulgarians but Pomaks. Muslim Slavs were not called Serbians (which only referred to Orthodox Slavs), but only Muslims (and later Bosniacs). Muslim Greeks were not called (and accepted as) Greeks, and these in massive numbers were exported to Turkey after the population exchange between the two states.
During and after the Balkan Wars, all Muslims of the region, irrespective of their ethnic identities, were seen as targets, and most of these were killed or forced to immigrate to Turkey. Out of millions of immigrants to Turkey, a small minority talked Turkish. The remaining populations in the Balkans are in very small numbers.
Albania had managed to transfer from a religious identity into a national identity, which any other nation in the region failed to do. Only Tito's Yugoslavia has managed to keep such an identity for some time, by calling people of the same ethnic background Yugoslavians instead of Serbian, Croatian or Bosniac, in accordance with their religions. But this failed with the fall of Yugoslavia and the tragic ethnic disasters.
Many ethnic greeks also converted to Islam but were expelled from mainland Greece and the islands after the independence of Greece and also in 1922. In Syria and Lebanon there are remnants of this community. I also know a Lybian friend of mine whose grandmother was Cretan (not Turkish) muslim.
I find Tyler's comment claiming that Islam was suited for Albanians because of their war-like temper inaccurate and un-scientific.
The very paradox of Ottoman history is that many Serbs, Greeks, Albanians, Armenians and Jews had prominent positions as governors and vizirs within the state. which is blatantly different from the case of the new Conversos in Spain whose conversion was not sufficient to even grant them citizenship and equal treatments as subjects of the King of Spain.
Egyptian monarchy up to 1952's revolution was Albanian and one of the most famous modern scholars of oral tradition (Hadith) in Islam was an Albanian born in Aleppo in northern Syria.
There were certainly episodes of forced conversions at times but very often the motives behind conversions were more natural just like with any other creed.
Albania was not the only country to have converted to Islam during the Ottoman Empire. (And for the record, there were Christian communities in Albania who survived the onslaught of forced Ottoman Islamic conversions. There are still Christian communities living throughout Albania....both Roman Catholic and particularly, Eastern Orthodox).
Bosnia, is another example of a Christian land that was conquered by the Ottomans and its population forcibly converted to Islam by the Ottomans.
However, the most historically notable example of forced Ottoman Muslim conversions in Christian lands.........was Turkey itself during the Late Middle Ages.
The country of Turkey, was once known as, "Asia Minor"-(the term dates back to the Roman conquest of this region 2000 plus years ago). The vast majority of Asia Minor's residents during the Late Middle Ages, were Greek Christians, with a minority presence of Armenian Christians. Sizable percentages of Greek and Armenian Christians living in Medieval Asia Minor, were conquered and converted by the Ottomans....from the Central interior, to the Western coast-(in particular).
So when looking at the Ottoman conversion campaign, much of Asia Minor, all of Bosnia, as well as the majority of Albania and Kosovo, were once, Christian lands converted by Ottoman Muslim Turks 500 plus years ago.
The conversion process lasted for hundred of years. -After the death of Scanderbeg, Albanian lands were totally under the Ottoman rule. Probably, at first in some zones of the country, force was used to convert people to Islam. -Another huge reason of conversion to Islam as a way of saving their ethnicity since they were surrounded by Slavs. Many orthodox Albanians in present-day Macedonia, Greece or Serbia lost their ethnic identity while Albanian Muslims didn't. Now days there are many cases of people declaring themselves as Albanians even though they already don`t speak their mother tongue. -Another reason was also the facilities offered to Muslims under ottoman rule such as : free taxes, better opportunities of military or political career. According to historic sources there were about 48 Albanian Grand Vezires in the Empire.
My family itself according to my grandfather converted to Islam around 200 years ago which it means 400 years after Ottoman empire invaded Balkans. The reason how they decided to convert is unknown to me.
One reason is that the Albanians were a "minority within a minority" in the Balkans. That is, they were the smallest of three Balkan groups including themselves, the Greeks and the Slavs.
The Albanians had earlier occupied Illyria which included both the former Yugoslavia, and the modern Albania. Up tp the 18th century, they were pushed further and further south within the recent "Yugoslavaia" by the (south) Slavs of the Austro-Hungarian empire. Finally, they constituted a majority only in the modern Albania and Kosovo.
By the late 18th century, the Balkans were at a crossroads. TheThe menacing Slavs, of course, were in an ascendancy, first under Austria-Hungary, and much later under "Yugoslavia." The Albanians were reluctant to join them, a wise decision, given late 20th century struggles between Bosnians, Serbs and Croats.
To the south lay the Orthodox Greeks who would free themselves from the Turks at the beginning of the 19th century, with whom the "Albanians" could not make common cause. (The Greeks were pushing north, threatening to encroach on Albanian territory.) Given the 18th century rise of both Russia and Austria-Hungary, even the Slavs that remained under Turkish rule (e.g. Bulgarians) could look forward to eventual "liberation."
The Albanians decided that their best bet was to remain with Ottoman Empire. Having come to this conclusion as a group, it made sense for many of them to convert to Islam to reduce their taxes, and to enjoy other privileges available to practitioners of the dominant faith.
This paid off in the 1870s when the Albanians formed the Albanian Defense League (this is a translation) against its Christian neighbors, with initial the approval of the Turks. Early in the 20th century, the Turks withdrew this approval but by 1912, the Albanians were ready to declare independence, given the impending collapse of the Ottoman Empire. This met with the support and approval of the Great Powers, who wanted to keep the coastal country away from the expansionist but land-locked Serbia.
To start off the word ''Arnaut'' means Albanian in Turkish, it has nothing to do with being a mercenary. The reason that Albanians became overwhelming Muslim did not happen until the time of the American Revolution. A few hundred years after the Ottomans invaded the area. Before the arrival of the Turks, a tiny percentage of Albanians did embrace Islam through the traders bringing in the concept. There are a few mosques that exist in Albanian lands that have a plaque on them declaring that they are NOT Ottoman Era mosques but rather from an era that preceded them. Yes it is true the Turks singled out Albanians more so than other nationalities because of their ruggedness and warrior like culture and honor as well as their loyalty that is heavily ingrained in their culture. But that is not a reason for them becoming Muslim. Many of the little boys kidnapped by the Ottomans were forced to become Muslim as they were little boys stolen from their families. Then raised to become soldiers then sent back to fight their own people and sent out to conquer other countries as well. Although the exact reason is not known why the majority did become Muslim, we can hint at a few perhaps. The main may have to do with being in synch with the powers that be and adopting their way of life so that they may prosper with land, titles of nobility and be accepted. For example if you look at Albania now, now that the West is occupying Albanian lands and the Christians hold the upper hand, a small percentage of Albanians have converted to Christianity. We must keep in mind that there has always existed until this day a large Christian Albanian population that never took on Islam. Why? It is not known. Sort of like why some Germans stayed Catholic while the majority became Lutheran. The question of why others didn't adopt it, well Albanians are not the only ones who adopted Islam. Many did adopt it. There are sizable Serbian Muslims, Croatian Muslims, Macedonian and Bulgarian Muslims, etc. Believe it or not although it is not much talked about. And yes it is safe to say that half of Greece became Muslim (although they no longer exist as Greece made sure Muslims were to be forcefully converted back to Christianity or risk being tortured or expelled). However the only majority Muslim ethnicity that has manifested itself to country in Europe is Albania. The next highest percentage of Muslims is Macedonia which is estimated to be at 50% from unofficial sources due to its high Albanian population as well as Macedonian Muslims in it. After that comes Bosnia which is 40% as the majority of Bosnians are Christian contrary to popular belief. Bosnians are no different than Serbs in their language and customs and heritage. I hope this answers the question.
Albania, was not the only country who became Muslim during the Ottoman period. You should also know that the country of Bosnia, (which was once Christian during the earlier Byzantine period), became Islamized during the Ottoman period.
There were also other Chrisitan populations in the Balkans who were converted to Islam during the Ottoman period; this included, a small number of Bulgarians, as well as small-moderate numbers of Greeks in living in Thrace, Macedonia and the island of Crete.
However, it was within the city of Constantinople proper whereby many of its centuries old Greek Christian residents were Islamized and Ottomanized. The surviving centuries old Greek Christian community of "The City", was a statistical minority throughout the Ottoman period.
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There were several factors to account for conversion, but the main one was that the culture of the Albanians was much more suited to Islam than to Christianity.
First of all, the rebellion of Skanderbeg in the 15th century infuriated the Pont, so after he was finally defeated, they made a special and determined effort to convert the Albanians to Islam. This gave them a toehold for the later growth in the country.
The main factor, however, was the warlike nature of the Albanians. Albania is a mountainous country and the people there have always never been simple farmers. They have often lived by sword and have a long tradition of being mercenaries, just like Skanderbeg. The style of rule there is "mountain chieftain" where each valley and hill has a mini warlord, who, in many cases ruled very tyranically over the locals. This political reality was much more conducive to the nurturing of Moslem tendencies over Christian ones. Even when Albania was a "Christian" land, they were notorious for being very fainthearted about it.
Another big factor is that the Turks kind of loved them for this. While the Turks treated other captive nations contemptuously and meanly, they loved Albanian military style and often hired them by the thousands as mercenaries, who were called Arnauts. Turks even dressed up their little boys in Arnaut soldier outfits, like we used to dress up boys in cowboy outfits. The Albanians were kind of the "Navy Seals" for the Turks. This created a bond between the Turks and Albanian chieftains who were heavily Moslem.
Ultimately, the upper classes and property owners in Albania became so dominantly Moslem that they were able to forcibly convert the whole country and this was done en masse.
