In 1463 the Ottomans secured the control of the region around the entrance to the Ambracian gulf. There was still no settlement called Preveza. Mehmed II was eager to conquer the Ionian islands and (perhaps) invade Italy, so he invested heavily in the defences of the gulf, since the Ottoman navy would use it as a base of operations. The Ottomans erected the castle of Bouka (from a word meaning “entrance”) next to the sea. The stone walls were reinforced with seven large round towers, while a wide trench protected the castle from the north. There were also numerous buildings within the walls, while a small town (Preveza) developed along the coastline to the northeast.