The Battle of Rocroi, fought on 19 May 1643, was a major engagement of the Thirty Years' War between a French army, led by the 21-year-old Duke of Enghien and Spanish forces under General Francisco de Melo only five days after the accession of Louis XIV to the throne of France after his father's death. Rocroi shattered the myth of invincibility of the Spanish tercios, the pike and shot infantry units that had dominated European battlefields for the previous 120 years. The battle is therefore often considered to mark the end of Spanish military greatness and the beginning of French hegemony in Europe in the second half-17th century during the reign of Louis XIV. After Rocroi, the Spanish progressively transformed the tercio system incorporating more of the line infantry doctrine used by the French over time.