the national library was founded in 1781 and from 1782 the clementinum was a legal deposit library. in 1918 the newly established czecho-slovak state took over the library. since 1990, it has been the national library. it contains a collection of mozartiana, material pertaining to tycho brahe and comenius, as well as historic examples of czech literature. the architecture is a notable example of baroque architecture and clementinum, covering 20,000 square metres, is the second largest complex of buildings in prague after the prague castle.