The Italian War of 1521–26
, sometimes known as the Four Years' War, was a part of the Italian Wars
that pitted Francis I of France
and the Republic of Venice
against the Holy Roman Emperor Charles V
, Henry VIII of England
, and the Papal States
. The conflict arose from animosity over the election of Charles as Emperor in 1519–20 and from Pope Leo X
's need to ally with Charles against Martin Luther
The war broke out across western Europe late in 1521 when the French invaded Navarre and the Low Countries. Imperial forces overcame the invasion and attacked northern France, where they were stopped in turn. The Pope, the Emperor, and Henry VIII then signed a formal alliance against France, and hostilities began on the Italian peninsula. At the Battle of Bicocca, Imperial and Papal forces defeated the French, driving them from Lombardy. Following the battle, fighting again spilled onto French soil, while Venice made a separate peace. The English invaded France in 1523, while Charles de Bourbon, alienated by Francis's attempts to seize his inheritance, betrayed Francis and allied himself with the Emperor. A French attempt to regain Lombardy in 1524 failed and provided Bourbon with an opportunity to invade Provence at the head of a Spanish army.
Francis himself led a second attack on Milan in 1525. While he was initially successful in driving back the Spanish and Imperial forces, his disastrous defeat at the Battle of Pavia, where he was captured and many of his chief nobles were killed, led to the end of the war. While imprisoned in Spain, Francis signed the Treaty of Madrid, surrendering his claims to Italy, Flanders, and Burgundy. Only a few weeks after his release, however, he repudiated the terms of the treaty, starting the War of the League of Cognac. Although the Italian Wars would continue for another three decades, they would end with France having failed to regain any substantial territories in Italy.