The Battle of Les Avins or Battle of Avein was fought on May 20, 1635 during the Thirty Years' War between a French and a Spanish army.
The battle was fought in the Belgian village of Les Avins, south of Huy, in what was then the bishopric of Liège. It was the first serious engagement for the French, which had entered the war only three months before.
The French army was under command of Marshals of France Urbain de Maillé-Brézé and Gaspard III de Coligny, Maréchal de Châtillon. The Spanish were commanded by Thomas Francis, Prince of Carignan.
The Spanish army was inferior in numbers, surrounded and completely defeated in just a few hours. Some 5,000 Spanish were killed or wounded, 1,500 captured and the rest scattered.The French army joined up with the Dutch coming from the north, but their disagreements gave the Spanish the time to reorganize themselfs. They harassed the French with quick cavalry raids. The French army also suffered from lack of supplies and money, what caused widespread desertions. After the Peace of Prague (1635), Imperial troops were free to reinforce the Spanish and in 1636 together they drove the French back, towards the gates of Paris.