I was reading about the Arbëreshë people in Italy, descendants of Albanians that fled the Ottomans and remained Christian. It made me wonder why certain parts of the Ottoman domain became so Islamicized while others didn't. For example, looking at things from a geographical perspective, why would a country like Bulgaria, so close to the Ottoman heartland, resist Islamicization, while Albania, on the outskirts and closer to the western world, became a success story for Islam?
Quite often it depends on the institutional strength of the church at the time of the Ottoman conquest. In the Bosnian case, the people there were converted at a relatively late date and because of the mountainous terrain and difficulties in communication the process was never really finished. Further, there were real questions about which faith the people there would follow. Either Orthodoxy from Bulgaria, Macedonia etc or the Catholicism which was firmly established in Hungary and Croatia. Further, the church mostly declined to involve itself in secular matters and was mostly concentrated in isolated monastic houses, they did not even officiate funerals. The eventual result was a weak church which was considered heretical by both and connected with the Bogomils. When the Ottomans arrived, the absence of a strong Christian identity and conflict between rival churches resulted in the gradual conversion of most of the Bosnian population to Islam.