Why did Jewish refugees from Spain settle in Bulgarian towns during the Ottoman period?

During the 15th and 16th centuries, Jewish refugees from the Christian West, including those from Spain, settled in Bulgarian towns because the Ottoman authorities permitted their immigration.12

This migration occurred following the widespread expulsion of Jews from Spain in 1492, where they had faced forced conversions and systemic persecution. While the majority of these refugees resettled in major centers such as Constantinople and Thessaloníki, many Bulgarian towns also acquired small Jewish communities. In these locations, the newcomers integrated with the existing Jewish population.312