The Italian Wars, also known as the Habsburg–Valois Wars, were a series of conflicts fought between 1494 and 1559, mostly in the Italian peninsula, but later expanding into Flanders, the Rhineland and Mediterranean Sea. The primary belligerents were the Valois kings of France, and their Habsburg opponents in the Holy Roman Empire and Spain. At different points, various Italian states participated in the war, some on both sides, with limited involvement from England and the Ottoman Empire.
The Italic League established in 1454 achieved a balance of power in Italy, but fell apart after the death of its chief architect, Lorenzo de' Medici, in 1492. Combined with the ambition of Ludovico Sforza, its collapse allowed Charles VIII of France to invade Naples in 1494, which drew in Spain and the Holy Roman Empire. Although Charles was forced to withdraw in 1495, ongoing political divisions among the Italian states made them a battleground in the struggle for European domination between France and the Habsburgs.
Fought with considerable brutality, the wars took place against the background of religious turmoil caused by the Reformation, particularly in France and the Holy Roman Empire. They are seen as a turning point in the evolution from medieval to modern warfare, with the use of the arquebus or handgun becoming common, along with significant technological improvements in siege artillery. Literate commanders and modern printing methods also make them one of the first conflicts with a significant number of contemporary accounts, including those of Francesco Guicciardini, Niccolò Machiavelli and Blaise de Montluc.
After 1503, most of the fighting was initiated by French invasions of Lombardy and Piedmont, but although able to hold territory for periods of time, they could not do so permanently. By 1557, the growth of Protestantism meant the major belligerents faced internal conflict over religion, forcing them to refocus on domestic affairs.