Lazare Hoche thus ordered a decisive assault on the night of 20 July against the fort de Penthièvre and its garrison of 4,000 men, despite a violent storm and the fort's being covered by the British naval guns.
 However, the Republican prisoners brought over as part of the Royalist force deserted and delivered the fort to Hoche by treachery, with many of its defenders being massacred.
 The British ships then opened fire on the fort, but their shots landed on Royalist, Republican and civilian alike.
 Joseph de Puisaye judged the situation hopeless and ordered his men to re-embark onto the admiral's flagship so as to limit the extent of the Royalist defeat and so, despite his later being accused of deserting to save his own life, 2,500 émigré and Chouan troops were evacuated in British rowing-boats.

Only Sombreuil and his men, cornered as they were, stood in the way of the Republican advance and they put up a last resistance.
 However, on the morning of 21 July Hoche and Sombreuil began negotiations and the Royalists capitulated shortly afterwards, apparently with the promise that the lives of all the Royalist troops would be spared.
Lazare Hoche thus ordered a decisive assault on the night of 20 July against the fort de Penthièvre and its garrison of 4,000 men, despite a violent storm and the fort's being covered by the British naval guns.  However, the Republican prisoners brought over as part of the Royalist force deserted and delivered the fort to Hoche by treachery, with many of its defenders being massacred.  The British ships then opened fire on the fort, but their shots landed on Royalist, Republican and civilian alike.  Joseph de Puisaye judged the situation hopeless and ordered his men to re-embark onto the admiral's flagship so as to limit the extent of the Royalist defeat and so, despite his later being accused of deserting to save his own life, 2,500 émigré and Chouan troops were evacuated in British rowing-boats.
Only Sombreuil and his men, cornered as they were, stood in the way of the Republican advance and they put up a last resistance.  However, on the morning of 21 July Hoche and Sombreuil began negotiations and the Royalists capitulated shortly afterwards, apparently with the promise that the lives of all the Royalist troops would be spared.
Invasion of France (1795)