sentences:  The fortress was declared a state prison in 1417; this role was expanded first under the English occupiers of the 1420s and 1430s, and then under Louis XI in the 1460s.The defences of the Bastille were fortified in response to the English and Imperial threat during the 1550s, with a bastion constructed to the east of the fortress.The Bastille played a key role in the rebellion of the Fronde and the battle of the faubourg Saint-Antoine, which was fought beneath its walls in 1652.