The combat of Mont Louis (5 September 1793) was a minor French victory during the War of the Convention that prevented a small French army under General Dagobert from being trapped in the mountains and distracted Spanish attention from the more important fighting around Perpignan.
While the main French and Spanish armies operated around Perpignan General Dagobert and the small corps of the Cerdanya operated against the Spanish left, which ran up the Tet valley to La Perche and Mont Louis on the Cerdanya plateau. Dagobert advanced west from Olette on the Tet to Mont Louis. On 28 August he attacked the Spanish camp at La Perche, and then continued to move west, to Puigcerdà and Bellver on the plateau, then down the Reo Segra to la Seu d'Urgell. He then turned east, and by early September was planned to attack Camprodon, to the south-east of the Cerdanya, a move that would have threatened the Spanish rear.
The Spanish commander, General Ricardós, responded to this threat by sending General Vasco up the Tet at the head of 3,500 men. Vasco defeated Berthencourt's brigade at Olette, and forced it to retreat west up the valley. Dagobert was in danger of being cut off, and so he abandoned his plans in the south and rushed back to Mont Louis. There he combined with Berthencourt and a small force that had been watching Villefranche, giving him a total of 3,000 men. On 4 September Dagobert drove Vasco out of strong positions to the east of Mont Louis, taking 300 prisoners and capturing 14 guns.
This success secured Dagobert's communications with the north. It also had an impact on the fighting around Perpignan, because it convinced Ricardós that he needed to send more troops, under the Comte La Union, to the Cerdanya. It also meant that when, in the aftermath of the Spanish capture of Peyrestortes and the French posts along the L'Agly on 8 September, the Convention at Perpignan was looking for a new commander of the Army of the Eastern Pyrenees, it would be Dagobert who was appointed to that post.