Aggelokastro, one of the main fortress complexs of Corfu, occupies a strategic position on the north end of the island controlling the south Adriatic Sea. Archaeological evidence suggest the hill was originally used in the 5th-6th century, while the site’s fortifications were possibly carried out by the Komninos dynasty, thought this is not substantiated be written sources, in their struggle to defend Corfu against the repeated raids of the Normans of Sicily.  Aggelokastro was seized in 1272 by the Angevins knights of Naples, as shown by the report of receipt of the Fortress, which is the earliest mention of Agelokastro.

Later, throughout the Venetian period, the fort ensured the security of the inhabitants of Corfu against aspiring Genoese and Ottomans conquerors and oversaw ship movement in the Adriatic. In this period the governor of the castle, also known as Kastellanos, was a nobleman appointed by the City Council of Corfu to serve for a year. In the 19th century Angelokastro fell in disuse and was finally abandoned. In 1999 the Ministry of Culture began a rescue and promotion project for the castle, funded by the European Union.

Αgelokastro hill is surrounded on the north and east by a low wall. The citadel sits atop this hill and is accessed via two gates, the main north gate protected by a round tower and the small gate on the south side. The ruins of the living quarters of the guard stationed at Angelokastro still stand opposite the main gate of the citadel, as well as parts of the walls’ ramparts on the NW corner of the fortifications, and three underground cisterns and tombs of unknown origin and date, carved into the rock to the west of the citadel.

Presently, the church of Archangel Michael sits at the highest point of the citadel; it is a rectangular building with a semicircular apse to the east. The church was built in the Late Byzantine and Early post-Byzantine period on the site of an earlier three nave basilica with narthex to the west and rectangular apse in the sanctuary , incorporating the SW part of the walls. The relief panel exhibited in the church and used as an altar, as well as the one in the chapel of Agia Kyriaki come from a 5th-6th century early Christian Church.
Although the fort was abandon, the church of Archangel Michael continued to function and every year celebrates the feast day of the Archangel. The small cave-hermitage chapel of Agia Kyriaki still survives at the east part of the castle and is decorated with wall paintings dated to the 18^th century.