St. Michael's Fortress (; ; formerly known as St. Anne's Fortress) is a medieval fort in Šibenik, Šibenik-Knin County, Croatia, situated on a steep hill above the old historic center of the city. Its strategically favorable and dominant position made it the central part of Šibenik fortification system. The location was more or less continuously occupied since the Iron Age, as is witnessed by numerous archaeological findings from the era. The city of Šibenik was first mentioned on 25 December 1066 in a charter signed by King Peter Krešimir IV and verified by his courtiers. It is widely considered that the signing took place at St. Michael's Fortress. Name St. Michael's Fortress was named after the oldest church in Šibenik, St. Michael's church, which was located inside its walls. One theory suggests that the church was built during the first wave of Christianization of Croatia, from the late 8th to the early 9th century. The first source that mentions St. Michael's church is a 12th/13th century hagiographic text Vita beati Ioannis episcopi et confessoris Traguriensis. During the Venetian rule, an unflattering name castel vecchio (old castle) was commonly used. The miraculous image of Madonna of the Castle, highly revered by the citizens of Šibenik, was originally kept inside St. Michael's church. In 1663, the church, along with a large part of the fortress, was destroyed when a lightning strike caused an explosion of a gunpowder magazine. During the renovation, a statue of St. Anne (the protector from storms) was brought to a small 16th-century church located below the southeastern walls of the fortress. This church came to be known as St. Anne's church, and the surrounding area became the city graveyard in 1828. As the centuries passed, and the fortress got permanently closed as a military facility, the citizens of Šibenik began calling it St. Anne's Fortress, after the often-used public area nearby. Architecture and history The importance of the fortress is evident not only in its favorable geographical position, but also in numerous archaeological findings, ranging from the Iron Age to 20th century. Throughout history, the fortress has been destroyed and rebuilt several times. Most of the fortress' structures can be dated to the early years of Venetian occupation, the early 15th century, but its numerous adaptations and interventions can be traced to mid-16th, early and mid-17th, mid-18th, and even early 19th centuries. As is typical for military architecture,