He would become a tenant of Glastonbury manor in Winterbourne Monkton in Wiltshire, and held a position as a marshal to the king of England.

Stacy, as well as other authors, mention Gilbert (Giffard) as a single person and as John Marshal's father.

John fought for Empress Matilda (Daughter of Henry I) in her unsuccessful struggle to gain the throne from her cousin, King Stephen, during the Anarchy.

[7] The historian Matthew Paris addresses the rapid extinction of the Marshal lineage to a curse bestowed upon the family by the bishop of Ferns, Albin O'Molloy, after unjust exactions on his diocese levied by William Marshal the elder.

Paris claims that when Ansel and his brothers were in their prime, their mother Isabel had foretold that “all would be earls of the same county”.