1494–1559, series of regional wars brought on by the efforts of the great European powers to control the small independent states of Italy. Renaissance Italy was split into numerous rival states, most of which sought foreign alliances to increase their individual power. It thus became prey to the national states that had begun to emerge in Europe. Foremost among those were France and Spain, whose prolonged struggle for supremacy in Italy was to curtail Italian liberties for more than three centuries.
The wars began when, in 1494, Charles VIII of France invaded Italy and seized (1495) Naples without effort, only to be forced to retreat by a coalition of Spain, the Holy Roman emperor, the pope, Venice, and Milan. His successor, Louis XII, occupied (1499) Milan and Genoa. Louis gained his next objective, Naples, by agreeing to its conquest and partition with Ferdinand V of Spain and by securing the consent of Pope Alexander VI. Disagreement over division of the spoils between the Spanish and the French, however, flared into open warfare in 1502. Louis XII was forced to consent to the Treaties of Blois (1504–5), keeping Milan and Genoa but pledging Naples to Spain.
Trouble began again when Pope Julius II formed (1508) an alliance against Venice with France, Spain, and Holy Roman Emperor Maximilian I (see Cambrai, League of). But shortly after the French victory over the Venetians at Agnadello (1509), Julius made peace with Venice and began to form the Holy League (1510) in order to expel the French “barbarians” from Italy. The French held their own until the Swiss stormed Milan (1512)—which they nominally restored to the Sforzas—routed the French at Novara (1513), and controlled Lombardy until they were defeated in turn by Louis's successor, Francis I, at Marignano (1515). By the peace of Noyon (1516), Naples remained in Spanish hands and Milan was returned to France.
The rivalry between Francis I and Charles V, king of Spain and (after 1519) Holy Roman emperor, reopened warfare in 1521, and the French were badly defeated in the Battle of Pavia (1525), the most important in the long wars. Francis was forced to sign the Treaty of Madrid (1526), by which he renounced his Italian claims and ceded Burgundy. This he repudiated, as soon as he was liberated, by forming the League of Cognac with Pope Clement VII, Henry VIII of England, Venice, and Florence.
To punish the pope, Charles V sent Charles de Bourbon against Rome, which was sacked for a full week (May, 1527). The French, after an early success at Genoa, were eventually forced to abandon their siege of Naples and retreat. The war ended (1529) with the Treaty of Cambrai (see Cambrai, Treaty of) and the renunciation of Francis's claims in Italy. France's two subsequent wars (1542–44 and 1556–57) ended in failure. Francis died in 1547, having renounced Naples (for the third time) in the Treaty of Crépy. Complete Spanish supremacy in Italy was obtained by the Treaty of Cateau-Cambrésis (1559), which gave the Two Sicilies and Milan to Philip II.
The wars, though ruinous to Italy, had helped to spread the Italian Renaissance in Western Europe. From the military viewpoint, they signified the passing of chivalry, which found its last great representative in the seigneur de Bayard. The use of Swiss and German mercenaries was characteristic of the wars, and artillery passed its first major test.