The Holy Roman Emperor was the title borne by the ruler of the Holy Roman Empire. Although some historical sources claim that the title originated with the Carolingian ruler Charlemagne in the year 800, modern scholars consider the title to be applicable to persons crowned from Otto I onwards.
Otto I was crowned the Holy Roman Emperor in 962 and the title carried through his dynasty until 1024. The title transferred to the Frankish dynasty from 1027 to 1125 and later to the Hohenstaufen dynasty from 1155 to 1197.
It then remained in the House of Habsburg from 1452 to 1740. While it was originally an autocratic title, it eventually became the title of the monarch who was elected by Prince-electors. The Holy Roman Emperor also had to be crowned by the Pope before claiming himself to be Emperor.
Although Charlemagne had laid the foundations of the Holy Roman Empire during his life, it was during Otto I’s reign in the 10th century that the Empire was firmly established on long-lasting foundations. Otto I was originally the king of the Germans who ascended to the position of the Holy Roman Emperor in 962 after he was crowned by Pope John XII.
He forged Italy together with his kingdom of Germany and remained the emperor of this vast territory until his death in 973. He also brought the Church under his control in Germany and was hailed as the savior of Christendom after he defeated the pagan Magyars. It was after him that the office of the Holy Roman Emperor continued to exist unabated for many centuries.
Frederick I was a German King of the Hohenstaufen dynasty. He was crowned the King of Germany in 1152 and went on to be crowned the King of Italy in 1155. He was crowned the Holy Roman Emperor by Pope Adrian IV the same year. When he ascended to the German throne, the might of the German kingdom was dwindling.
He restored the power of the monarchy in Germany and immediately set to gain control of Italy. He was able to take control of most of northern Italy by 1155 but had to confront rebellions in the region throughout the rest of his life. He also came into disagreements with the Papacy and kept attempting throughout his reign to subdue the Church in subordination to the Emperor. His long reign as the Emperor came to an end in 1190.
Frederick II was another Hohenstaufen Holy Roman Emperor. Like Frederick I, Frederick II was very ambitious, charismatic, a very able ruler, and constantly in conflict with the might of the Church. He was the King of Germany from 1212 to 1220, the King of Sicily from 1198 to 1250, and the King of Jerusalem from 1225 to 1228.
In 1220, he became the King of Italy and was crowned the Holy Roman Emperor, a title he kept until 1250.
He was notable for his evasive attitude towards the Fifth and Sixth Crusades, an attitude that contributed significantly to the Christian losses in the Holy Land. He famously wore a robe with an Arabic congratulatory inscription at his coronation and was generally considered a religious skeptic. He also actively promoted arts and literature throughout his reign.