text: Charles V was the last Holy Roman Emperor to be crowned by the Pope .
simplified: Holy Roman Emperor was the title that was given to the ruler of a loose group of places in what is now called Germany called the Holy Roman Empire . The title of `` emperor '' was passed from the Romans to the Frankish kingdom when , on 25 December 800 , Pope Leo III crowned Charlemagne , king of the Franks , emperor of the Holy Roman Empire .