Niš

Every army marching between the Danube and Constantinople had to pass through Niš, and the city changed hands with each war. Murad I took it in 1385 after a siege of 25 days. John Hunyadi's crusade won it back for the Serbian despot Đurađ Branković in 1443, but it was lost again in 1448, this time for nearly two and a half centuries. Austrian armies took it in 1689 and again in 1737, holding it only briefly each time. Once Belgrade had fallen to the Habsburgs in 1717, Niš became the Ottomans' bulwark on this road, and between 1719 and 1723 they raised a great fortress on the Nišava over the ruins of older works. In 1809, after Serbian rebels were crushed at nearby Čegar, the Ottoman commander had the heads of the fallen set into a tower, ever after called the Skull Tower.