Battle of Villalar: King Charles I of Spain defeats the Comuneros.

The Battle of Villalar was a battle in the Revolt of the Comuneros fought on 23 April 1521 near the town of Villalar in Valladolid province, Spain. The royalist supporters of King Charles I won a crushing victory over the comuneros rebels. Three of the most important rebel leaders were captured, Juan de Padilla, Juan Bravo, and Francisco Maldonado. They were executed the next day, effectively ending armed resistance to Charles I.

Charles V was Holy Roman Emperor and Archduke of Austria from 1519 to 1556, King of Spain from 1516 to 1556, King of Sicily and Naples from 1516 to 1554, and also Lord of the Netherlands and titular Duke of Burgundy from 1506 to 1555. He was heir to and then head of the rising House of Habsburg. His dominions in Europe included the Holy Roman Empire, extending from Germany to northern Italy with rule over the Austrian hereditary lands and Burgundian Low Countries, and Spain with its possessions of the southern Italian kingdoms of Sicily, Naples, and Sardinia. In the Americas, he oversaw the continuation of Spanish colonization and a short-lived German colonization. The personal union of the European and American territories he ruled was the first collection of realms labelled "the empire on which the sun never sets".

The Revolt of the Comuneros was an uprising by citizens of Castile against the rule of Charles I and his administration between 1520 and 1521. At its height, the rebels controlled the heart of Castile, ruling the cities of Valladolid, Tordesillas, and Toledo.