Complex sentence: Besides Croatian and Hungarian recruits from the territories of Habsburg Monarchy, the Croats were composed of soldiers recruited all over Eastern Europe, such as Serbs, Albanians, Transylvanians, Poles, Cossacks, Wallachians and Tatars.
Split into simpler sentences: Besides Croatian and Hungarian recruits from the territories of Habsburg Monarchy, the Croats were composed of soldiers recruited all over Eastern Europe. However, the Croats comprised men recruited all over Eastern Europe including Croats, Hungarians, Serbs, Albanians, Transylvanians, Poles, Cossacks, Wallachians and Tatars.