s the strength of some old Byzantine fortifications in Angelokastro, Kassiopi, Gardiki and others, was another strong factor that enabled Corfu to remain the last bastion of free, uninterrupted Greek Christian civilization in the southern Balkans after the fall of Constantinople. Will Durant claims that Corfu owed to the Republic of Venice the fact that it was the only part of Greece never conquered by the muslim Turks.
A series of attempts by the Ottoman Turks to take the island began in 1431 when Turkish troops under Ali Bey landed on the island, tried to take the castle and raided the surrounding area, but were repulsed.
The Siege of Corfu (1537) was the first great siege by the Ottomans. It began on 29 August 1537, with 25,000 soldiers from the Turkish fleet landing and pillaging the island and taking 20,000 hostages as slaves. Despite the destruction wrought on the countryside, the city castle held out in spite of repeated attempts over twelve days to take it, and the Turks left the island unsuccessfully because of poor logistics and an epidemic that decimated their ranks.
Thirty-four years later, in August 1571, Turkish forces returned for yet another attempt to conquer the island. Having seized Parga and Mourtos from the Greek mainland side they attacked the Paxi islands. Subsequently they landed on Corfu's southeast shore and established a large beachhead all the way from the southern tip of the island at Lefkimi to Ipsos in Corfu's eastern midsection. These areas were thoroughly pillaged as in past encounters. Nevertheless the city castle stood firm again, a testament to Corfiot-Venetian steadfastness as well as the Venetian castle-building engineering skills. It is also worth mentioning that another castle, Angelokastro, situated on the northwest coast near Palaiokastritsa (Greek: Παλαιοκαστρίτσα meaning Old Castle place) and located on particularly steep and rocky terrain, a tourist attraction today, also held out
