in 1912 Serbia, Greece, Bulgaria and Montenegro declared war on the Ottomans. The Ottomans quickly lost territory. According to Geert-Hinrich Ahrens, "the invading armies and Christian insurgents committed a wide range of atrocities upon the Muslim population." In Kosovo and Albania most of the victims were Albanians while in other areas most of the victims were Turks and Pomaks. A large number of Pomaks in the Rhodopes were forcibly converted to Orthodoxy but later allowed to reconvert, most of them did.During this war hundreds of thousands of the Turks and Pomaks fled their villages and became refugees. Thessaloniki and Adrianople were crowded with them. By sea and land mostly they settled in Ottoman Thrace and Anatolia.

Hey, oboxtobot.

The Ottomans had a policy of not forcing religion, but many inhabitants in newly conquered regions did choose to convert to Islam. The most prevalent regions for this were Albania, Kosovo, Bosnia, Crete and north-eastern Bulgaria. While the expansion of the Ottoman Empire continued up until 1683, all new lands would have had Muslim populations to some extent. For example, the modern day area of Slavonia in Croatia is reported to have had some 50 mosques, while the area of Dalmatia in Croatia also had Islamic influence up to the regions held by the Venetians. One example of this is the old town of Vrana, held by Jusuf Maskovic, an Islamicized Croat. So, beginning in 1683 the Ottoman Muslims in the black regions on this map were expelled. In Croatia, Hungary and Transylvania, it is believed that most Muslims went to Bosnia, northern Greece or were killed/converted.

As for the orange regions on this map, they fell in the 18th century after the Peace of Karlowitz in modern day Sremski Karlovci, Serbia. The Muslims in these regions were believed to have mainly gone to Bosnia, others were converted and killed.

There were many Ottoman Muslims in the Bessarabia, Yedisan and Podolia areas corresponding roughly to modern day Ukraine and Moldova. With Russian imperial expansion (which was really the main cause for the persecution and destruction of Ottoman Muslims) these lands were invaded and the population (mostly Nogai and Crimean Tatars) are believed to have gone to the Dobruja region of modern day Romania and Bulgaria, from where many went to Turkey and others were assimilated into the modern Turkish population.

Then comes the Greek war of independence in 1821, whereby the Morea region became independent. There were many Muslims in these regions but all were expelled during the war of independence or massacred. A notable example of this would be either the Navarino or Tripolitsa massacres. So, by the mid-19th century, there were no more Ottoman Muslims in the Morea, most had gone to then Turkish-controlled Greek Macedonia or Western Thrace.

Then we get to the Serbian uprising in 1830. Again, the Muslims from the Sanjaks of Smederevo, Uzice and all in Karadorde's new state [seen here] (https://upload.wikimedia.org/wikipedia/commons/4/4d/Serbia1809.png). These almost all went to Bosnia or to Turkey. Ivo Andric wrote about these refugees in his book Cuprija na Drini.

So, the next big thing were the Balkan Wars of 1912-13. The main victims of this were Muslims who were from modern-day Greece, Bulgaria, Macedonia and Montenegro. These became well known as muhacir, and almost all expelled went to Turkey (Istanbul, to be precise), as they had nowhere else. During this period, Bulgarian and Montenegrin Muslims also fled to Turkey, as did Cretan Turks, mostly to the Aegean part of Turkey. After this, the 1923 population exchange made sure that Muslim areas in modern day Greece (Crete, Larissa, Thessaloniki, Kastoria, Ioannina) were expelled of Muslims who were in turn traded for Turkish-speaking Christians from Anatolia, one example being the Karamanlides.

Hope this helped.