The design of a new structure to replace the old ruined castle of Poppelsdorf commenced in 1715 at the request of the owner, Joseph Clemens, Archbishop-Elector of Cologne, who engaged the French architect Robert de Cotte. Clemens wanted a maison de plaisance that would be near his remodeled Bonn Palace one-half mile to the north. There was to be a canal between the two, following the example of the Palace of Versailles and the Trianon de Marbre.
Work came to a halt after Clemens' death in 1723, but his nephew and heir, Archbishop of Cologne Clemens August, undertook a second campaign of construction in 1745–1746.
Under the Prussian rule, in 1818 the Palace and the nearby Park became part of the University of Bonn. In the same year the Park was converted to the Botanical Garden of Bonn, which today contains about 0.5 hectares of greenhouse area with eleven greenhouses and about 8.000 different plants.
In 1944 the Palace was heavily damaged by an Allied air attack. It has been rebuilt in a much simpler appearance from 1955 on.
References:The Clementinum is a historic complex of buildings in Prague. Until recently the complex hosted the National, University and Technical libraries, the City Library also being located nearby on Mariánské Náměstí. The Technical library and the Municipal library have moved to the Prague National Technical Library at Technická 6 since 2009. It is currently in use as the National Library of the Czech Republic.
Its history dates from the existence of a chapel dedicated to Saint Clement in the 11th century. A Dominican monastery was founded in the medieval period, which was transformed in 1556 to a Jesuit college. In 1622 the Jesuits transferred the library of Charles University to the Klementinum, and the college was merged with the University in 1654. The Jesuits remained until 1773, when the Klementinum was established as an observatory, library, and university by the Empress Maria Theresa of Austria.