which empire was king charles v of spain from
RECOMMENDED READING. The Reign of Charles V is an important new study of one of the most important rulers in world history. As the Holy Roman Emperor and King of Spain during the mid-1500s, Charles V ruled the first truly global empire and was the greatest of all the Habsburg Emperors.
Habsburg power peaked when, via strategic marriage, a single Habsburg came to be (simultaneously) the Spanish king and Holy Roman emperor. This man is known as Charles V (Holy Roman emperor) or Charles I (king of Spain). Charles' dual reign spanned roughly four decades, near the beginning of the Reformation period.