In 1273, he became the 13th Lord of Abergavenny on the death of his childless uncle, Sir George de Cantilupe, and thereby acquired Abergavenny Castle and the vast lands of the honour of Abergavenny. He also inherited many Cantilupe estates including Aston Cantlow in Warwickshire, one of that family's seats.
He died in February 1313, aged 50, and was succeeded in the barony by his eldest son John Hastings, 2nd Baron Hastings. He and his first wife Isabel de Valence were buried (together with his parents) in the Hastings Chapel of the Greyfriars Monastery in Coventry, Warwickshire (founded circa 1234), commemorated by effigies.[9] According to Dugdale (1666)[6] quoting from an inscription in ancient French, the stained glass windows of this chapel displayed coats of arms including: Hastings, Cumyn (wife of brother Edmund Hastings), Cantilupe, Valence, de Spenser and Huntingfield (husband of daughter Joan Hastings).[10]
^“He … is recorded to have been present in pleno parliamento domini Regis on the morrow of Trinity 18 Edw. I [29 May 1290] with other magnates et proceres tunc in parliamento existentes, whereby he is held to have become LORD HASTINGES….In the Hastings Peerage claim in 1840-41 the Committee for Privileges of the House of Lords, following the recommendation of Lord Chancellor Cottenham, decided that the presence of Sir John de Hastings in this Parliament was pursuant to the issue of a writ of summons to him, and resolved accordingly.” Cokayne, The Complete Peerage, 2nd edition, Volume VI, p. 347