The Italian War of 1551–1559 began when Henry II of France declared war against Holy Roman Emperor Charles V with the intent of recapturing parts of Italy and ensuring French, rather than Habsburg, domination of European affairs. The war ended following the signing of the Treaty of Cateau-Cambrésis between the monarchs of Spain, England and France in 1559. Historians have emphasized the importance of gunpowder technology, new styles of fortification to resist cannon fire, and the increased professionalization of the soldiers.

Henry II was King of France from 1547 until his death in 1559. The second son of Francis I and Duchess Claude of Brittany, he became Dauphin of France upon the death of his elder brother Francis in 1536.