Listed as one of the Companions of William the Conqueror in the late 19th century version of the Battle Abbey Roll. This roll has no authority. Its plausible participated in the Battle of Hastings, but not proven. He likely served with William the Conqueror at some time during the Norman conquest. He was accused, possibly unjustly, of participating in a baronial revolt initiated by Robert de Mowbray, earl of Northumbria.
Took part in the First Crusade. Died during the Siege of Antioch.

Wikipedia https://en.wikipedia.org/wiki/Ernulf_de_Hesdin