"[1] The tower had hardly been finished when it was captured by the army of Charles V, Holy Roman Emperor, led by the Connetable de Bourbon, when he invaded Provence.
The Connetable avoided a long and costly siege by simply paying the commander of the fort 500 ecues to surrender.
"[1] When the Imperial army left, the fort was used to imprison the chevalier Bertrande de la Garde, who had fought for Charles V against Francis I.
In 1679, Louis XIV sent his chief military architect, Vauban, to make the fortifications of Toulon strong enough to resist a British attack.
[4] He recommended adding another level of cannons, and a new battery at the foot of the tower, and lowering the hills around to give the gunners a clearer view of approaching enemy ships.
It became primarily a place to lock up military prisoners, Corsican rebels, and, during the French Revolution, first royalists and then supporters of the Republic.
The underground cells were filled in, and the chapel, barracks and hospital were removed, but the casemates, circular galleries and embrasures for the cannon still remain as they were.