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 Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.