February 5th, 1556 -

Kings Henri I and Philip II sign the Treaty of Vaucelles

The Italian War of 1551 (1551–1559), sometimes known as the Habsburg-Valois War, began when Henry II of France, who had succeeded Francis I to the throne, declared war against Charles V with the intent of recapturing Italy and ensuring French, rather than Habsburg, domination of European affairs. An early offensive into Lorraine was successful, with Henry capturing the three episcopal cities of Metz, Toul, and Verdun, but the French invasion of Tuscany in 1553, in support of Siena attacked by an imperial‐Tuscany army, was defeated at the Battle of Marciano by Gian Giacomo Medici. Siena fell in 1555 and eventually became part of the Grand Duchy of Tuscanyfounded by Cosimo I de' Medici.

The Treaty of Vaucelles was signed on February 5, 1556 between Philip II of Spain and Henry II of France. Based on the terms of the treaty, the territory of Franche-Comté was relinquished to Philip. However, the treaty was broken shortly afterwards.