Lucens Castle's strategic location allowed it to control the Broye valley, which was an important transit corridor. Starting in the Middle Ages and until 1536 it was a residence of the Bishop of Lausanne and served to control the Bishop's land in the Broye valley. During the 12th century, the castle was repeatedly destroyed and rebuilt. In 1476, it was destroyed by the Swiss Confederation. In 1536 the valley and the surrounding territory were conquered by Bern. It became the seat of a Bernese bailiwick at the same time. In 1542, the vogt of Moudon moved into the castle.
The castle was enlarged between 1579–86 and served as an arsenal and fortress on the border to Fribourg. In 1798, the Bernese were forced out and the Canton of Léman was formed. Shortly thereafter, the castle became the property of Canton, who sold it 1801 to private individuals. In 1925, it was converted into a Swiss Reformed institute for girls. Between 1965-70, it was the seat of the Conan Doyle Foundation, and is now in private hands.
References: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.