King Charles V was the ruler of both Spanish Empire and the Holy Roman Empire during the 6th century.
He consequently became the most powerful ruler in Europe, with colonies in Americas as well as Asia. During most of his reign, Charles was involved in wars against many enemies, most notably France and the German princes.
Charles V’s mother, Queen Joanna, became the ruler of the crowns of Castile and Aragon upon the death of King Ferdinand II in 1516. At the time, the territories of the two crowns included most of modern-day Spain and Italy as well as colonies in Asia and the New World.
Spanish colonies in the New World provided Charles V with huge amounts of bullion with which he would go on to fund his near-continuous military campaigns.
The Holy Roman Emperor, Maximilian, died in 1519. The German princes then had Charles V elected as the new Emperor. Charles was consequently crowned by the Pope in 1519 and became the new Holy Roman Emperor.
However, Charles’s rule in the Holy Roman Empire wasn’t without trouble. This was a period when Protestantism and Reformation were spreading in Germany and Charles opposed both throughout warfare and diplomacy.
He won a major victory against Protestant German princes in 1547 but ultimately had to agree to the 1555 Peace of Augsburg which split Germany along Catholic and Protestant lines.
During Charles’ reign, France was surrounded on all sides by Habsburg dominions. This led to a near-continuous conflict between France and Charles through most of his reign.
The first of many wars between the two began in 1521 with the French military campaign headed by Francis I. The war resulted in a victory for Charles V who captured Francis I after defeating the French.
Subsequently released, Francis I launched a second war against Charles as part of the League of Cognac brought together by Pope Clement VII. Again, Charles stood victorious and after sacking Rome, imprisoned the Pope and forced France to give up claims on Italian territories.
The third war between France and Charles erupted in 1535 over claims to the duchy of Milan. Although France sought to defeat Charles by forging an alliance with the Ottomans, the alliance between England and Charles forced the two sides to sue for peace after an inconclusive war.