Page "Frederick I, Holy Roman Emperor" Paragraph 16

Frederick in the meantime was focused on restoring peace in the Rhineland, where he organized a magnificent celebration of the canonization of Charles the Great ( Charlemagne ) at Aachen, done under the authority of the antipope Paschal III.

Concerned over rumours that Alexander III was about to enter into an alliance with the Byzantine Emperor Manuel I, in October 1166, he embarked on his fourth Italian campaign, hoping as well to secure the claim of Paschal III, and the coronation of his wife Beatrice as Holy Roman Empress.

This time, Henry the Lion refused to join Frederick on his Italian trip, tending instead to his own disputes with neighbors and his continuing expansion into Slavic territories in northeastern Germany.

He began besieging Ancona in 1167, which had acknowledged the authority of Manuel I ; at the same time, Frederick's forces achieved a great victory over the Romans at the Battle of Monte Porzio.

Heartened by this victory, he lifted the siege of Ancona and hurried to Rome where he not only had his wife crowned empress, but he also received a second coronation at the hands of Paschal III.

Unfortunately, his campaign was stopped by the sudden outbreak of an epidemic ( malaria or the plague ), which threatened to destroy the Imperial army and drove the emperor as a fugitive to Germany, where he remained for the ensuing six years.

During this period, Frederick decided conflicting claims to various bishoprics, asserted imperial authority over Bohemia, Poland, and Hungary, initiated friendly relations with Manuel I, and tried to come to a better understanding with Henry II of England and Louis VII of France.

Many Swabian counts, including his cousin the young Duke of Swabia, Frederick IV, died in 1167, so he was able to organize a new mighty territory in the Duchy of Swabia under his reign in this time.

Consequently, his younger son Frederick V became the new Duke of Swabia in 1167, while his eldest son Henry was crowned King of the Romans in 1169, alongside his father who also retained the title.