Over several centuries, Bosnia found itself at the centre of struggles between great powers and civilizations, which all left their imprint on the land and people as the hilltop towns with their churches and castles were taken one by one. Ottoman forces advanced slowly through the Balkans in the late medieval period and their arrival was anticipated. Fleeing the conquerors, Orthodox Serbs had started to pour into Bosnia from the 1430s onwards. By 1451 the Ottomans had taken Sarajevo, much of the rest of Bosnia fell in 1463 and Hercegovina by 1481. Jajce remained under the Hungarians until 1527 after the Turks lost possession of the town. Bihać was the last Bosnian city to fall and by the sixteenth century the Ottomans were in control not only of modern-day Bosnia and Hercegovina, but also Lika and parts of Slavonia known as the Bosnian Eyalet from 1580. What defeat by the Turks actually meant to ordinary Bosnians we can surmise from the surviving fragments of evidence, but it is likely to have been traumatic for many. Dalmatia served a safe haven for those escaping from Ottoman rule and many of its cities had fortifications erected to protect them against Turkish incursions. The family of the Renaissance humanist who experimented with the design of the parachute, Faust Vrančić (known also by his Venetian name Fausto Veranzio), is believed to have fled from Bosnia in the sixteenth century and settled in Sibenik. Some Bosnians were sold into slavery in the empire. Some seized the moment to change religion. Stjepan Hercegović, brother of the last Christian ruler of Hercegovina Vladislav, changed his name to Ahmed in 1473 and served the sultan as grand vizier in Constantinople. A tekija or Sufimonastery was built in the second decade of the sixteenth century on the Buna river near Blagaj and became well-known for Dervish religious devotion.