Zvíkov is a castle on a rocky spur in the South Bohemian Region, originally Přemyslid, built in the 13th century and administered by the National Heritage Institute.

Zvíkov is a castle on a rocky spur in the South Bohemian Region, administered by the National Heritage Institute. According to the institute's website, it has been linked with the Přemyslid dynasty from the beginning and ranks among the most important works of Czech secular medieval architecture.[1]
The Přemyslid period
The castle was probably founded by Ottokar I, who in 1226 exchanged the Oslov estate, belonging to the monastery in Doksany, for six other villages and thus also gained the spur on which the castle was built. Construction is best documented under Wenceslaus I. In 1234 the sources mention the burgrave Konrád of Janovice, so the castle must already have been partly built.[1] When Prince Ottokar rebelled against his father in July 1247, only Zvíkov, together with Loket and Most, remained loyal to Wenceslaus. Wenceslaus I received the delegation of the rebels and the nobility here, led by Nicholas, Bishop of Prague, and had its members imprisoned in the tower.[1]
Under Ottokar II, construction continued under the burgrave Hirza, appointed in 1250. The main work on the royal palace and the fortifications began then, and the building workshop was also active in Písek and Myšenec.[1]
Late Middle Ages and the early modern period
After the Přemyslid line died out in the male line in 1306, the castle was acquired by Henry of Rožmberk. It enjoyed its greatest fame under Charles IV, who had it repaired and liked to stay there. Until Karlštejn was completed, the coronation jewels were kept here temporarily.[1] The castle then changed owners frequently and was held in pledge mainly by the Rožmberk and Švamberk families. During the Hussite Wars it was unsuccessfully besieged by the Taborites in 1429. In 1437 it was again acquired by Oldřich of Rožmberk.[1]
Zvíkov remained royal property until the last third of the 16th century, when it passed by sale to the Švamberks, which was entered in the land tables in 1575. They carried out extensive Renaissance alterations that did not disturb the original character of the building. The castle withstood attackers during the Thirty Years' War as well, and in 1622 the garrison surrendered to a superior force, after which the castle was plundered by the imperial army.[1] In 1623 it was acquired by the Eggenbergs and, after their line died out in 1719, by the Schwarzenbergs.[1]
Restoration
After the family was divided in 1790, Zvíkov passed to the younger branch, represented by Marshal Karel I Schwarzenberg, who resided at Orlík. Securing works began at that time, first the repair of the chapel and the rescue of the late Gothic paintings. The masonry of the royal palace was in poor condition, and in 1829 the New Gate collapsed, after which part of the palace above the river slid down. After 1880 the reconstruction of the palace and the walls therefore began. The original stone elements have a slightly pinkish colour and are easy to tell apart from the new parts. The works ended at the close of the 19th and the beginning of the 20th century. The castle belonged to the Schwarzenbergs until 1948.[1]