Grandisson was born in 1292 at
Ashperton near
Hereford, the second son of five of Sir
William Grandisson (died 1335). Sir William was the heir of
Otto de Grandson (died 1328), close personal friend of
King Edward I, and head of the English branch of a family that was based at
Grandson Castle, now in
Switzerland. His mother, Sybil (died 1334), was a younger daughter and co-heir of Sir John de Tregoz. He studied at Oxford in 1306, then from 1313 to 1317 he studied theology at the
University of Paris under Jacques Fournier, who later became
Pope Benedict XII. He returned to study at Oxford 1326–7. Later in
Avignon he became the
chaplain and friend of
Pope John XXII, who
mentored him and sent him on
diplomatic missions. The Pope rewarded Grandisson by making him
prebendary at York, Wells, and Lincoln, and, in October 1310,
Archdeacon of Nottingham. Grandisson donated the tenor bell in the south tower of Exeter Cathedral. Named "Grandison" and re-cast at least three times, most recently in 1902 by
John Taylor & Co, the current bell bears the inscription "EX DONO IOHANNIS GRANDISON EPISCOPI EXON GVLIELMVS EVANS FECIT 1729". During his episcopacy, he faced a number of
anticlerical movements in Devon. For example, the
Order of Brothelyngham—a fake
monastic order of 1348—regularly rode through Exeter, kidnapping both religious and laymen, and extorting money from them as ransom. He also outlawed a popular cult that was being promoted by a house of
canons at
Frithelstock Priory.
Death and burial Grandisson died at Chudleigh on 16 July 1369 and was buried in the chapel on the south side of the central doorway of the west front of
Exeter Cathedral, a chapel that he had caused to be built. ==Surviving works of art==