The Spanish drove the outnumbered French soldiers out of their camp near Mas Deu and compelled them to retreat to Perpignan.

The victory enabled the Spanish forces to lay siege to the Fort de Bellegarde, which dominated the best road through the Pyrenees from Barcelona into France.

On April 17, 1793, Captain General Antonio Ricardos began the invasion of France when he descended on Saint-Laurent-de-Cerdans in the French Cerdagne with 4500 Spanish troops.

The Spanish next headed for Céret on the Tech where they encountered one French regular battalion, 1000 volunteers, and four artillery pieces on 20 April.

[1] The Captain General left a force at Le Perthus to watch the garrison of the Fort de Bellegarde and keep it from interfering with his supply convoys.

At about the same time, the French brigadier general, Luc Siméon Auguste Dagobert and Colonel Eustache Charles d'Aoust arrived with reinforcements from the Army of Italy.

The French army was encamped on a hill 80 metres (262 ft) high near Mas Deu, which is located east of Trouillas.

[3] The Chateau of Mansus Déi was built by the Knights Templar in the 12th century and used as an administrative center for their extensive properties in Roussillon.

In its heyday, the Templar establishment raised cattle, grapes, olives, and other crops on lands that stretched from Fenouillèdes in the north to Banyuls-sur-Mer in the south.

The 4680-strong Spanish left wing was led by Juan de Courten, Rafael Adorno, and José Crespo.

[3] De Flers' staff worked out a plan whereby the French artillery would bombard the Spanish positions, pinning their infantry in place.

[3] Ricardos planned to maneuver Conde de la Unión's cavalry and then send Courten's Walloon Guards on a sweep around the village of Thuir to hit the flank of the Mas Deu camp.

Apparently this ended the action for the day, with the French troops holding firm despite the prolonged artillery barrage.

[7] On the 18th, Ricardos reorganized his center, placing José Urrutia y de las Casas and Juan Manuel Cajigal in charge of the reserve cavalry.

Rather than follow up his badly shaken opponents, Ricardos chose to turn back and invest the Fort de Bellegarde.

On the Spanish side, Osuna proved to be a difficult subordinate and was transferred to the Army of Navarre in the western Pyrenees in October.