From the Middle Ages onward the nobles of the Simiane-Agoult family were among the most powerful rulers in Haute Provence. Faithful to its motto « The Towers support the Lilies », the family produced high stewards, bishops, governors and ambassadors for the kingdom of France. There are traces of the Simiane-Agoult family found all over Provence, but it is to their home fiefdom, Simiane, that they gave the first part of their name.
The second part of the name of their stronghold comes from the Rotonde whose powerful conical structure dominates the village. Built at the end of the 12th century to strengthen the defences of the castle, it was saved in 1841 by Prosper Mérimée, who had it declared an Historic monument. Remarkable for its 19 metres height, the massive exterior conceals a magnificent ceremonial room with a twelve-ribbed cupola, hight quality stonework, columns decorated with stylised leaves of water plants, and sculpted human masks. The Rotonde is recognised as a very fine example of civil and military Romanesque architecture and is the perfect setting for the highly reputed annual festival of early music, “Les Riches Heures Musicales de la Rotonde”.