The first castle at Bonaguil was constructed after the middle of the 13th century, on a rocky spur, probably by Arnaud La Tour de Fumel. The single entrance to the keep, built above a natural cave, was a door six metres up, accessible by ladder.
It was entirely restructured at the end of the 15th and beginning of the 16th centuries by Bérenger de Roquefeuil, who added all of the defensive improvements of the end of the Middle Ages. The main danger at the end of the 15th century came from artillery. For protection, it was necessary to keep the enemy's cannons at a distance. An external wall, 350 m in length, was added to the castle, with lower curtains retaining a mass of earth which cushioned the artillery shots. This curtain wall was reinforced with small towers and equipped with guns.
When Bérenger died in 1530, the castle was not yet adapted for siege warfare, but it remained an imposing fortress. During the Wars of Religion, the two brothers fought in opposite camps, and the castle was taken in 1563. A first restoration took place in 1572. In debt, Antoine had to give the fortress to the lord of Pardhaillan in 1618, before being able to buy it back several years later.
François de Roquefeuil, a distant relative with some claim to the castle, took possession of it in 1656, kept and pillaged it for almost a year before abandoning it.
In the 18th century the earthworks to the west of the castle were enlarged and laid out as a large terrace and became a pleasant promenade. New apartments were built in the south, outside the inner wall, thus benefitting from a better outlook.
As well as being an impressive feat of military engineering, the Chateau Bonaguil is also a lovely chateau to visit.
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.