An old fortification of the Frankopans, built during the wars against the Turks, Slovin was first mentioned in the 12th century. The old fort was property of the Frankopan family since the 15th century, joined by an old Franciscan monastery from the same period. Later, this town has been called Slunj. In the 16th century the town was ravaged by the Ottoman wars and turned into a military outpost of the Croatian Military Frontier, but by the end of the 17th century the settlement was rebuilt into the Slunj as it exists today. The castle has been developed to a fortress and served as headquarters for the commanding general of this area.
References:The Gravensteen is a castle in Ghent originating from the Middle Ages. The name means 'castle of the counts' in Dutch. Arnulf I (918–965), Count of Flanders, was the first to fortify this place, building a medieval bastion on this high sand dune, naturally protected by the river Leie and its marshy banks. This bastion consisted of a central wooden building and several surrounding buildings, also in wood.
In the early 11th century, the wooden building was replaced by a stone residence, consisting of three large halls that made up three storeys, connected by a stone stairwell. The monumental stone staircase, the light openings, the fireplaces built into the walls and the latrines were signs of considerable luxury and comfort in those days. There was probably also a tower.