Which French chief minister declared war on Spain in 1635?

The French chief minister who declared war on Spain in 1635 was Cardinal Richelieu.

Armand Jean du Plessis, better known as Cardinal Richelieu, served as Louis XIII’s principal minister from 1624 until his death in 1642. Although France was a Catholic power, Richelieu viewed the Habsburg dynasty—especially Spain and the Holy Roman Empire—as France’s greatest strategic threat.

Before 1635, France supported Habsburg opponents through subsidies, diplomacy, and limited interventions while avoiding open war. The Swedish defeat at Nördlingen in 1634 changed that calculation. France then entered the conflict directly, and the declaration of war on Spain began the Franco-Spanish War, which lasted until 1659.

Richelieu’s policy was driven more by state security and the balance of power than by religious alignment. That is why he supported Protestant Sweden and the Dutch Republic despite being a Catholic cardinal. Mazarin succeeded him after his death, while Colbert belonged to a later generation of French ministers.