Begun as a hunting-lodge in 1162, the château was enlarged by Philip II Augustus in 1183 and by Louis IX in 1248 and was one of the favourite residences of the Capet dynasty. The donjon, begun by Philip VI in 1337 and completed 1370, is a square building (h. 54 m) with cylindrical corner towers. In 1653 Cardinal Jules Mazarin became governor of Vincennes and employed Louis Le Vau to build two symmetrical blocks either side of the south entrance, one pavilion each for the king and queen. Le Vau also designed the monumental south entrance. Later in the 18th and 19th centuries it functioned as a state prison. In 1860 Napoleon III, having employed Viollet-le-Duc to restore the keep and the chapel, gave the Bois de Vincennes (9.95 km² in extent) and its château to Paris as a public park.