In what year was Charlemagne crowned as the head of the Holy Roman Empire?

Charlemagne was crowned as the head of the Holy Roman Empire in the year 800 AD. This event marked a significant moment in European history, as it symbolized the revival of the Western Roman Empire and the unification of much of Western Europe under Charlemagne’s leadership. The coronation took place on December 25, 800, during a ceremony at St. Peter's Basilica in Rome, where Pope Leo III placed the crown on Charlemagne's head. This act was pivotal in establishing a relationship between the church and the state, and it laid the groundwork for the future power dynamics within Europe. The other options provided do not correspond to the time frame or context of Charlemagne’s reign or coronation.