The summons to the King's Court was the last straw, for the defendant in this Court was entirely at the mercy of the Crown.

"When, in Anglo-Norman times you speak of the King's Court, it is only a phrase for the King's despotism."[6] Anselm took no notice of the King's summons, and decided to appeal to Rome.

For a time William refused permission for any departure from England, but he yielded in 1097, and Anselm set out for Rome.
He stayed at Rome and at Lyons till William was dead, for the Pope would not let him resign Canterbury, and could do nothing to bring the King to a better mind.

Then, on the urgent request of Henry I., he returned to England, and for a time all went well.

Henry was in earnest for the restoration of law and religion in England, and his declaration, at the very beginning of his reign--the oft-quoted "charter" of Henry I .-- to stop the old scandals of selling and farming out Church lands, and to put down all unrighteousness that had been in his brother's time, was hailed with rejoicing.
Anselm stood loyally by Henry over the question of his marriage with Edith (who claimed release from vows taken under compulsion in a convent at Romsey), and his fidelity at the critical time when Robert of Normandy and the discontented nobles threatened the safety of the Crown was invaluable.
But Henry was an absolutist, anxious for all the threads of power to be in his own hands; and just when a great Church Council at the Lateran had decided that bishops must not be invested by kings with the ring and staff of their office, because by such investiture they were the king's vassals, Henry decided to invite Anselm to receive the archbishopric afresh from the King's hands by a new act of investiture.