Dictionary of National Biography, 1885-1900/Mohun, John de (1270?-1330)
MOHUN, JOHN de (1270?–1330), baron, lord of Dunster in Somerset, son of John de Mohun, the grandson of Reginald de Mohun [q.v.] and Eleanor Fitzpiers, was about nine years old at his father's death in 1279, and was a ward of Edward I (Lyte, p. 16). He received many summonses to perform military service as in 1297 to serve in Flanders, in 1299 to join the muster at Carlisle, which was afterwards put off and held at York on 12 Nov., and again in 1300 to serve against the Scots. At the parliament held at Lincoln in January 1301 he joined in the letter of the barons to the pope, and is therein described as 'dominus de Dunsterre' (Fœdera, i. ii. 926). He was summoned to the muster at Berwick on 24 June, and again to the muster to be held at Berwick on 25 May 1303. He was at Perth early in 1304, for he dined there with the Prince of Wales on Candlemas day. He was a conservator of the peace for the county of Somerset in 1307, and in 1308 and 1309 was summoned to do service against the Scots. In 1311 he held a commission as one of the king's justices. He joined the party of Thomas, earl of Lancaster, and was concerned in the execution of Gaveston, for which he received a pardon in 1313 (ib. ii. i. 231). Summonses were sent to him to serve against the Scots in 1315, 1316, and 1319. In 1321 he was warned to abstain from the parliament that the Earl of Lancaster designed to hold at Doncaster (ib. pp. 442, 459). He gave charters to the priories of Dunster and Bruton, and to the townsmen of Dunster (Lyte). Certain lands in Ireland [see under Mohun, Reginald de] he exchanged with the king for the manor of Long Compton in Warwickshire (ib.; Fœdera, i. ii. 949). He died in 1330.
He married first Ada, daughter of Robert, or Payn, Tiptoft, by whom he had seven sons and a daughter, and secondly a wife named Sybilla (Lyte). From Sir Reginald, his fifth son, descended the Mohuns of Cornwall, of which house were the Mohuns, barons of Okehampton (ib. p. 37). His eldest son, John, was a knight-banneret, was present at the battle of Boroughbridge, and, dying in Scotland perhaps in 1322, was, it is said, buried in the church of the Grey Friars at York (ib.; Parliamentary Writs, ii. iii. 1177); he married Christian, daughter of Sir John Segrave, by whom he had a son, John (1320–1376) [q. v.], who succeeded his grandfather (Lyte).
[Lyte's Dunster and its Lords, privately printed, and largely from papers in the Archaeological Journal, contains full information, with references, concerning John and the house of Mohun generally; Dugdale's Baronage, ii. 498; Cal. of Docs., Scotland, ii. No. 1516 (Rolls Ser.); Prynne's Parliamentary Writs, i. 740, ii. iii. 1176, 1177; Rymer's Fœdera, i. ii. ii. i. passim.]