Kingdom of France Ottoman Empire. The course of the war saw extensive fighting in Italy, France, and the Low Countries , as well as attempted invasions of Spain and England. The conflict was inconclusive and ruinously expensive for the major participants. The war arose from the failure of the Truce of Nice , which ended the Italian War of — , to resolve the long-standing conflict between Charles and Francis—particularly their conflicting claims to the Duchy of Milan.
Having found a suitable pretext, Francis once again declared war against his perpetual enemy in Fighting began at once throughout the Low Countries ; the following year saw the Franco-Ottoman alliance 's attack on Nice , as well as a series of maneuvers in Northern Italy which culminated in the bloody Battle of Ceresole.
Charles and Henry then proceeded to invade France, but the long sieges of Boulogne-sur-Mer and Saint-Dizier prevented a decisive offensive against the French. Henry, left alone but unwilling to return Boulogne to the French, continued to fight until , when the Treaty of Ardres finally restored peace between France and England.
The Truce of Nice, which ended the Italian War of — , provided little resolution to the long conflict between the Holy Roman Emperor and the King of France; although hostilities had ended, giving way to a cautious entente, neither monarch was satisfied with the war's outcome. Francis continued to harbor a desire for the Duchy of Milan , to which he held a dynastic claim; Charles, for his part, insisted that Francis comply at last with the terms of the Treaty of Madrid , which had been forced on the French king during his captivity in Spain after the Italian War of — Negotiations between the two powers continued through and into In , Francis invited Charles—who faced a rebellion in the Low Countries —to travel through France on his way north from Spain.
Francis soon began gathering new allies to his cause. On 4 July , however, the French ambassador to the Ottoman court, Antoine de Rincon , was killed by Imperial troops as he was travelling near Pavia. By the end of September, Charles was in Majorca , preparing an attack on Algiers ; Francis, considering it impolitic to attack a fellow Christian who was fighting the Muslims, promised not to declare war for as long as the Emperor was campaigning.
