One obstacle to the organized pilgrimage to God was, Dr. John Rao argues, failure to recognize papal guidance of the line of march. Opposition came from the Eastern Churches, led by the restored Byzantine Emperors and the Patriarchs of Constantinople, as well as from Holy Roman Emperors, Kings, and many bishops in the West. Thirteen century popes--and the Council of Lyons with its supporter--tried many ways to overcome this resistance. Taken from: Christianity in the Late Middle Ages-Early Renaissance - 1996 VonHildebrand Institute