Ioannina Castle encloses the historic core of a city built on a rocky peninsula projecting into Lake Pamvotis. Archaeological work has identified Hellenistic defenses beneath later walls, although the ancient settlement’s name remains uncertain. Ioannina first appears securely in a decree of Byzantine emperor Basil II in 1020, and Anna Komnene described its fortified citadels during Norman campaigning in 1082. The walls protected an administrative, commercial, and religious center whose position connected Epirus with routes toward Macedonia, Thessaly, Albania, and the Adriatic coast.

After Constantinople fell to the Fourth Crusade in 1204, Ioannina became part of the Despotate of Epirus. Byzantine, Epirote, Serbian, and Italian rulers competed for the city before it voluntarily submitted to the Ottoman Empire in 1430 under negotiated terms. The walled town contained two principal citadels: a northeastern stronghold associated with governors and the larger southeastern Its Kale, or inner fortress. Churches, residences, workshops, markets, baths, and water systems developed inside a densely inhabited urban enclosure rather than an isolated military post.

An unsuccessful Christian uprising led by Dionysius the Philosopher in 1611 brought violent reprisals and the expulsion of Christians from the castle. The church of Saint John in the northeastern citadel was replaced by the Aslan Pasha Mosque complex in 1618, with a mosque, tomb, religious school, and kitchen. Jewish and Muslim communities remained important within the walls, while Christian neighborhoods expanded outside. Ioannina prospered through trade, education, craft production, and especially the skilled silversmithing for which the city became widely known.

Ali Pasha of Tepelena made Ioannina the center of a powerful semi-autonomous domain from 1788. He rebuilt the defenses on a massive scale, completed artillery terraces by 1815, and transformed Its Kale into a palace complex with barracks, kitchens, baths, treasury buildings, and the rebuilt Fethiye Mosque. Ottoman forces besieged him in 1821–22, damaging the palace before his defeat and execution. Ioannina remained Ottoman until the Greek army captured the city during the First Balkan War in 1913.

The castle survives as a lived-in quarter containing homes, streets, museums, mosques, churches, synagogal memory, and archaeological remains. The Aslan Pasha Mosque houses the Municipal Ethnographic Museum, while Its Kale includes the Byzantine Museum and a museum devoted to silversmithing. Conservation reveals ancient, Byzantine, and Ottoman masonry without reducing the place to a single era. Ioannina’s importance lies in this continuity: successive rulers refortified the same peninsula, but generations of residents made the enclosed town a diverse civic landscape as well as a stronghold.