Persecution from evil men ‘for justice sake’ is hard to bear, and to suffer it patiently is one of the eight beatitudes. St William's way of sanctity lay in the path of persecution from saints and other holy people, with an admixture of interested parties. Almost everything he did, and any circumstance of his conduct, was twisted to his condemnation. These attacks began the moment he was elected to the see of York and ceased only when the grave closed over him.

Little is known of his life before his election. He was the son of a nobleman named Herbert from whom he received his surname, and his biographer Thomas Stubbs, a York Dominican, writing about 1340, adds that his mother was Emma, the sister of King Stephen. On this late authority it has been generally assumed that he was that king's nephew. We have no clue to his age.