Leo IX

Pope Leo IX (21 June 1002 – 19 April 1054), born Bruno of Egisheim-Dagsburg, was Pope from 12 February 1049 to his death in 1054. He was a German aristocrat and a powerful ruler of central Italy while holding the papacy. Leo is widely considered the most historically significant German Pope of the Middle Ages. His citing of the Donation of Constantine in a letter to the Patriarch of Constantinople brought about the Great Schism between the Catholic and Orthodox churches.

In 1053, Leo led an army against the Normans in southern Italy, but his forces suffered total defeat at the Battle of Civitate. From June 1053 to March 1054 the Pope was held hostage at Benevento, until he acknowledged the Norman conquests in Calabria and Apulia. He did not long survive his return to Rome, where he died on 19 April 1054.