Charles I of Spain, who by birth already held sway over much of Europe and Spanish America, is elected the successor of his late grandfather, Holy Roman Emperor Maximilian I. Charles, who was also the grandson of Ferdinand II and Isabella of Spain, had bribed the princes of Germany to vote for him, defeating such formidable candidates as King Henry VIII of England, King Francis I of France, and Frederick the Wise, the duke of Saxony.

Crowned as Emperor Charles V, the new Holy Roman emperor sought to unite the many kingdoms under his rule in the hope of creating a vast, universal empire. However, his hopes were thwarted by the Protestant Reformation in Germany, a lifelong dynastic struggle with King Francis, and the advance of the Ottoman Turks into Europe. In 1558, after nearly four decades as Holy Roman emperor, Charles abdicated the throne in favor of his brother, Ferdinand. He had already granted much of the other European territory under his rule to his son Philip.