Santa Maria in Domnica
Frederick held a canonry in St. Lambert's Cathedral in Liège and then became the archdeacon. In 1049, or perhaps 1051, he met Pope Leo IX, and was invited to Rome. He was appointed cardinal-deacon of Santa Maria in Domnica by Leo IX. He was also appointed "bibliothecarius et cancellarius", in succession to Odo, the primicerius of Toul, who was named a bishop, and whose latest signature as chancellor is on 16 January 1051. Frederick appears as a signatory to papal documents from 9 March 1051 to 21 December 1053.