In antiquity the wider region witnessed repeated invasions by the Athenians, the Achaeans, the Macedonians, and the Romans, who destroyed the cities on the mainland and forced people to seek refuge on the island. During the Byzantine period, the island lived in relative peace; when the Crusaders occupied Constantinople (1204), the Venetians claimed Aitoliko as a link to their extensive maritime network in the eastern Mediterranean. The Ottoman conquest (1501) caused much suffering, but by the 1760s Aitoliko had grown prosperous and controlled a large fleet of sailing ships. It was mercilessly plundered by Albanians in the 1770s and was heavily taxed by Ali Pasha of Ioannina.