Soon after taking his doctor's degree he was promoted to be provincial of his order in England. An official document dated 1456 is quoted by White Kennet (Parochial Antiquities, 1818, ii. 399) in which Capgrave, as provincial, recognises a claim to the patronage of the convent of Austin Friars at Oxford, then existing near the site of Wadham College.
A few more facts relating to his life can be gathered from his work ‘De illustribus Henricis.’ In 1406, when a boy, he saw the Princess Philippa, daughter of Henry IV, embark at Lynn, on her way to marry Eric XIII, king of Norway, Sweden, and Denmark (p. 109). In 1422 he was studying in London at the time of the birth of Henry VI (p. 127). In 1446 he received the king when he visited the Austin Friary at Lynn, and gave him an account of its foundation (p. 137). It may be presumed that he was then head of the house. In the dedicatory epistle prefixed to his ‘Commentary on the Acts of the Apostles’ he refers to a visit to Rome, where he was taken ill; but he does not specify the date (De illustr. Henricis, app. p. 221).
Capgrave's biographers eulogise his character in the highest terms. The most learned of English Augustinians whom the soil of Britain ever produced, he was distinguished as a philosopher and theologian, practically rejecting in his writings the dreams of sophists, which lead only to strife and useless discussions. Fulfilling the mission of his order, ‘it was his wont to thunder against the wanton and arbitrary acts of prelates, who enlarge the borders of their garments beyond measure, catching at the favour of the ignorant herd; not shepherds, but hirelings, who leave the sheep to the wolves, caring only for the milk and fleece; robbers of their country and evil workers, to whom truth is a burden, justice a thing of scorn, and cruelty a delight’ (Bale).
His chief patron was Humphrey, duke of Gloucester, whose life he wrote, and to whom he dedicated certain of his works. He died at Lynn on 12 Aug. 1464 (not 1484, as Pamphilus and Pits say), in his seventy-first year.
Capgrave was a most industrious writer; lists of his works are given by Bale, Tanner, and others. In Latin he wrote: 1. Commentaries on the several books of the Pentateuch, on Joshua, Judges, and Ruth, the four books of Kings, Psalms, Ecclesiastes, Isaiah, Daniel, the twelve Minor Prophets, Acts, Pauline and Canonical Epistles, and the Apocalypse. 2. ‘Manipulus Doctrinæ Christianæ.’ 3. ‘De Fidei Symbolis.’ 4. ‘Super Sententias Petri Lombardi.’ 5. ‘Determinationes Theologicæ.’ 6. ‘Ad Positiones erroneas.’ 7. ‘Orationes ad Clerum.’ 8. ‘Sermones per Annum.’ 9. ‘Lecturæ Scholasticæ.’ 10. ‘Ordinariæ Disputationes.’ 11. ‘Epistolæ ad diversos.’ 12. ‘Nova Legenda Angliæ.’ 13. ‘Vita S. Augustini.’ 14. ‘De sequacibus S. Augustini,’ and (the same work or a continuation) 15. ‘De illustribus viris Ordinis S. Augustini.’ And the historical works: 1. ‘De illustribus Henricis.’ 2. ‘Vita Humfredi Ducis Glocestriæ.’ His works in English were: 1. ‘The Life of St. Gilbert of Sempringham.’ 2. A metrical ‘Life of St. Katharine.’ 3. ‘A Chronicle of England from the Creation to A.D. 1417.’ ‘A Guide to the Antiquities of Rome,’ in English, a work which he is supposed to have written during his detention there from illness, has also been ascribed to him (Chronicle, p. 355).
The commentaries on Genesis and the Pauline Epistles (and probably some others of the biblical commentaries) were dedicated to Humphrey, duke of Gloucester; the commentary on the books of Kings to John Lowe, bishop of St. Asaph (1433–44); and the commentaries on the Acts and the Apocalypse to William Grey, bishop of Ely (1454–78). The ‘De illustribus Henricis’ was dedicated to Henry VII, the ‘Chronicle’ to Edward IV. The ‘Life of St. Gilbert’ was dedicated to Nicholas Resby, master of the order of Sempringham.
Very many of Capgrave's works are lost. Those which have appeared in print or are still extant in manuscript are as follows:—The autograph manuscript of the ‘Commentary on Genesis’ (a work written in 1437–8), which was presented to Duke Humphrey, is preserved in Oriel College, Oxford, MS. No. 32. It was given by the duke to the university, as one among 135 volumes, in February 1443–4; other works of Capgrave, included in the same gift, being the commentaries on Exodus and on 1 and 3 Kings. A manuscript of the commentary on the Acts, also said to be autograph, was given by Bishop Grey, of Ely, to Balliol College, and is now marked No. 189. Another manuscript in the same college, No. 190, contains Capgrave's work on the Creeds, the autograph manuscript being that in the library of All Souls' College, No. 17. It is in this latter work that he latinises his name as ‘Johannes de Monumento Pileato.’ The prologues to the commentaries on Genesis, the Acts, and the Creeds are printed in the Rolls edition of the ‘De illustribus Henricis.’ The ‘Nova Legenda Angliæ,’ compiled from the work of John of Tynemouth, exists in a manuscript in the York Minster Library; another copy in the Cottonian Library (Tiberius E. i) has been greatly injured by fire;