The Castle was built by the Roman Emperor and Czech King Charles IV in 1348–57. The castle was intended as a stately and safe depository for the Imperial and Bohemian Crown Jewels as well as the extensive Imperial collection of holy reliquaries. The core of the castle consists of the rectangular Imperial Palace, a smaller residential tower with the Church of the Virgin and the particularly valuable St. Catherine's Chapel. The ideological centre of Karlštejn Castle is the residential Great Tower with the Chapel of the Holy Cross. At the end of the 19th century the castle underwent extensive re-Gothicization under the supervision of the Czech architect Josef Mocker. Given the state of the castle in the early 19th century, this extensive renovation has resulted in the preservation of a monument of immense historical and artistic value.