 Condé had sallied out of Paris to prevent the advance of the royalist forces under the command of Turenne.Condé's forces became trapped against the city walls and the Porte St Antoine, which the Parliament refused to open; he was coming under increasingly heavy fire from the Royalist artillery and the situation looked bleak.In a famous incident, La Grande Mademoiselle, the daughter of Gaston, the Duke of Orléans, convinced her father to issue an order for the Parisian forces to act, before she then entered the Bastille and personally ensured that the commander turned the fortress's cannon on Turenne's army, causing significant casualties and enabling Condé's army's safe withdrawal.