 As the Second Bulgarian Empire fell under full-scale Ottoman rule in the 14th-15th century whereas the lands north of the Danube were still contested between the Europeans and the Ottomans and then came under Ottoman suzerainty, but retained their internal autonomy, many Bulgarian fled the Ottoman occupation in various periods and settled in what is today Romania.These included both Bulgarian Orthodox and some Roman Catholics (either former Paulicians from the central Bulgarian north or from Chiprovtsi in the northwest).The migratory waves were particularly strong after the Austro-Turkish and Russo-Turkish Wars of the 17th-19th century.