He was created Cardinal Deacon of S. Giorgio in Velabro by Pope John XXIII in the consistory of 15 December 1958. Resigning as Dean on 18 December that year, Jullien was appointed Titular Archbishop of Corone by Pope John on 5 April 1962.
He was appointed Cardinal Deacon of S. Giorgio in Velabro by Pope John XXIII in a consistory on 15 December 1958. He stepped down as Dean on 18 December that year, and then was named Titular Archbishop of Corone by Pope John on 5 April 1962.