The Friedberg castle was subsequently built to serve as a border security and customs post for the Duchy of Bavaria and Swabia, but put the town in opposition to the free city of Augsburg. It was built between 1257-1264 by Duke Ludwig II.
The castle was the cause of the first burning of Friedberg by Augsburg in 1396. The town was subject to the many frequent wars between Swabia, Bavaria and Augsburg.
A revival in the town's fortunes came when, in 1568, the Duchess Christine chose Friedberg castle as her seat following her husband's death. The town became the centre of Bavarian court life, but was short lived when the town was ravaged by the plague in 1599. More suffering came as the town was sacked twice by the Swedes during the Thirty Years War. After the war only the town hall, castle and city walls were left standing.
The castle is situated on a spur of and has an unusually deep moat. Since the renovation in 1982, Friedberg castle has been a museum.
The Château de Foix dominates the town of Foix. An important tourist site, it is known as a centre of the Cathars. Built on an older 7th-century fortification, the castle is known from 987. In 1002, it was mentioned in the will of Roger I, Count of Carcassonne, who bequeathed the fortress to his youngest child, Bernard. In effect, the family ruling over the region were installed here which allowed them to control access to the upper Ariège valley and to keep surveillance from this strategic point over the lower land, protected behind impregnable walls.
In 1034, the castle became capital of the County of Foix and played a decisive role in medieval military history. During the two following centuries, the castle was home to Counts with shining personalities who became the soul of the Occitan resistance during the crusade against the Albigensians.