Pope Leo IX (, , 21 June 1002 – 19 April 1054), born Bruno von Egisheim-Dagsburg, was the head of the Catholic Church and ruler of the Papal States from 12 February 1049 to his death in 1054. Leo IX is considered to be one of the most historically significant popes of the Middle Ages; he was instrumental in the precipitation of the Great Schism of 1054, considered the turning point in which the Catholic and Eastern Orthodox Churches formally separated. Wikipedia