A promising leader, Mirabel was killed in action while leading his troops at the Battle of Sant Llorenç de la Muga.

On 12 May 1793, the Representatives on mission appointed Mirabel cavalry instructor for the departments of Gard and Hérault, with the rank of lieutenant.

[2] The commander of the French Army of the Eastern Pyrenees, Louis-Charles de Flers instructed Luc Siméon Auguste Dagobert and 5,000 to defend Mas Deu.

[2] On this occasion, Ricardos mounted a direct assault of the camp at Perpignan but was driven off by well-handled French artillery.

At this, Barbantane panicked and cravenly abandoned his army, leaving Eustache Charles d'Aoust in command at Perpignan and Jacques Gilles Henri Goguet leading an outlying division at Salses-le-Château.

[9] At the Second Battle of Boulou on 30 April 1794, Mirabel commanded a brigade in Charles-Pierre Augereau's Right Division in Jacques François Dugommier's Army of the Eastern Pyrenees.

[10] On 6 May, Augereau defied orders and advanced to seize Sant Llorenç de la Muga where the Spanish had a cannon foundry.

Since its garrison was running short of provisions, Conde de la Unión determined either to break the siege or to send a food convoy into the fortress.

The Spanish commander ordered a major attack on 13 August 1794, which resulted in the Second Battle of Sant Llorenç de la Muga.

Though Augereau's troop deployment was inadequate, his tactical skill helped win the battle and inflict heavy losses on the Spanish.