Overview
Sir William Arundel KG (born about 1369, died 1400) was a Knight of the Order of the Garter, Constable of Rochester Castle and Constable and Warden of Reigate Castle. He owed all his appointments to Richard II whose reign (1377-1399) covered most of Arundel's life.
Family background
Arundel was the son of John FitzAlan, 1st Baron Arundel and the grandson of Richard FitzAlan, 10th Earl of Arundel.
His mother was Eleanor Maltravers, daughter and heiress of Sir John Maltravers and the granddaughter (and, eventually, sole heiress) of John Maltravers, 1st Baron Maltravers.
Sir William Arundel's family used the surname Arundel rather than FitzAlan but in most cases his relations have been re-designated as FitzAlans by subsequent writers and historians. That was not done in his case, and he is always referred to as Sir William Arundel.
From Wikipedia (CC BY-SA 4.0).