According to Prof. Oliver Jens Schmitt, the Serbs played a key role as supporters of the Ottomans during their expansion into the Balkans and in the capture of Constantinople. One of the most decisive moments was the Second Battle of Kosovo, where they thwarted a possible alliance between Gjergj Kastrioti and the Hungarian leader, Janos Hunyadi.

During this period, especially the regions of northern and central Albania were hit hard by the Ottoman campaigns, being almost completely destroyed. Some of the inhabitants were forced to take refuge in the mountainous areas, while others moved outside the Balkans, establishing Arbëresh communities in Italy.