MOSTYN, Sir Roger (c.1566/8-1642), of Mostyn Hall, Flints. and Gloddaith, Caern.

Published in The History of Parliament: the House of Commons 1604-1629, ed. Andrew Thrush and John P. Ferris, 2010
Available from Cambridge University Press



Family and Education

b. c.1566/8,1 2nd but 1st surv. s. of Sir Thomas Mostyn† of Mostyn and Gloddaith and 1st w. Ursula, da. and h. of William Goodman, alderman of Chester.2 educ. Brasenose, Oxf. 1584; Thavies’ Inn; L. Inn 1588.3 m. 2 Aug. 1596, Mary (d. 25 Feb. 1654), da. of Sir John Wynn†, 1st bt. of Gwydir, Llanrwst, Caern. 6s. incl. John* (2 d.v.p.) 2da.4 kntd. 23 May 1606.5 suc. fa. 21 Feb. 1618.6 d. 18 Aug. 1642.7 sig. Roger Mostyn.

Offices Held

J.p. Flints. 1601-d. Caern. 1621-d.;8 sheriff, Flints. 1608-9;9 commr. sewers, R. Dee 1607, Denb. 1609, subsidy, Flints. 1608, 1621-2, 1624-5, 1628, Caern. 1621-2, 1624, subsidy arrears, Flints. and Caern. 1626;10 member, Council in the Marches 1617-d.;11 dep. lt. Flints. 1618-d.;12 commr. oyer and terminer, Wales 1624-d., survey Rhuddlan and Flint castles, Flints. 1624, knighthood fines, Caern. and Flints. 1630-2, piracy, Flints. 1631, Exch. arrears, Wales 1632, charitable uses, Flints. 1633, 1642, exacted fees, Cheshire and Flints. 1635, array, Flints. 1642.13


The Mostyns claimed descent from Tudur Trevor, a tenth-century prince of Powys, and may have been stewards to the princes of Powys Fadog in the final decades of Welsh rule. They were, however, of little significance in the century following the Edwardian conquest, though one married a sister of Owen Glynd┼Ár, and their estates were briefly forfeited during the latter’s rebellion of 1400. Thereafter, they acquired extensive estates in Anglesey, Flintshire and Creuddyn in north-eastern Caernarvonshire through marriage. They supported the claims of their relatives Jasper and Henry Tudor to the English throne, but tradition states that Henry’s offer of a place at Court after the battle of Bosworth was declined.14

Although they remained in Wales, the family did not escape the Anglicizing influences of the Tudor period. Thomas and Peter Mostyn† adopted the surname of Mostyn (the family’s principal residence) in the 1530s, and family members occasionally served as knights for Flintshire thereafter. The subject of this biography, and his step-brother Piers Griffith of Penrhyn, were among the first members of the family to be given an English education, and Mostyn later chose an English tutor for his eldest son Thomas, while several of his younger children were schooled at Hawarden ‘in respect of the English tongue’.15 Yet while Mostyn corresponded largely in English, his interests remained firmly focused on north Wales, at least until his sons John*, William and Richard embarked on careers in London during the 1620s. Furthermore, in an age of declining gentry patronage, the Mostyns remained keen supporters of the bardic tradition. The eisteddfodau of 1523 and 1567 were held on their estate at Caerwys, Flintshire, and Sir Roger’s marriage was one of the last great gatherings of the bardic order. While many of these poetical tributes were written to order, the ethos of service to the local community which they commended had a profound influence upon Sir Roger’s values.16

Mostyn’s English education may have been intended as the foundation for a career in the Church or the law, but the death of his elder brother William in about 1586 left him as heir to the estate. He apparently took control of the Mostyn coalmines during his father’s lifetime; these yielded a lucrative income of £700 per annum, which he used to buy lands worth £300 a year.17 In his marriage negotiations with Sir John Wynn†, 1st bt., Mostyn was anxious ‘that few should be acquainted with my particular estate’, perhaps because Mostyn manor was held on a Crown lease. In 1603-5 Mostyn contested the mining rights with his kinsmen Piers Mostyn of Talacre and Sir John Egerton*, and he only secured his title in 1614, when Wynn bought the manor from the Crown. Even so, he later clashed with customs officials, observing that he was not liable for customs on coal shipments to Ireland.18

Mostyn was fortunate in having an independent income, as he had a stormy relationship with his father. The quarrel probably began in May 1600, when Mostyn was pressured to assign the family’s Gloddaith estate - part of which had earlier been promised to his own wife - to his new stepmother, Dame Katherine, as a jointure. However, in 1608, when Sir Thomas and his wife separated, Mostyn helped to negotiate the complicated arrangements for the maintenance of all parties.19 Mostyn was much closer to Wynn than to his own father: the sole letter which survives from the period of the marriage negotiations suggests that they were initiated by Mostyn; and the two men raised their families together. They were also involved in each other’s business interests: Mostyn attempted to persuade Bishop Morgan of St. Asaph to lease the tithes of Llanrwst to Wynn in 1604; and, on a visit to London shortly thereafter, he contacted Sir Thomas Myddleton I* and Sir Thomas Fleming I* about a match for Wynn’s eldest son. Later, when Mostyn’s search for a bride for his eldest son coincided with Wynn’s for a wife for his second son, (Sir) Richard Wynn*, they briefly considered a joint match with the daughters of Sir Francis Darcy*.20 Mostyn was also a friend in adversity: he broke a confidence to warn Wynn that his attempt to arbitrate a dispute with the tenants of Dolwyddelan, Caernarvonshire would not be accepted; and later encouraged Wynn to appeal against a heavy fine imposed by the Council in the Marches for intimidating Crown tenants.21 By contrast, Mostyn was not on speaking terms with his own father in 1614, and when Sir Thomas fell mortally ill in February 1618 he refused to see his heir. While the family entail settled most of the estate on Sir Roger, his father bequeathed him nothing ‘but some old plate which my grandmother had given me’.22 Mostyn was confident that he could come to a private agreement with his estranged stepmother, whose interests had also been ignored by the will, but for fear that Sir Thomas would sign away his goods before his death, he set a guard at Mostyn. He eventually secured £2,000 in cash and goods, and his father died before he could do any more damage to Mostyn’s inheritance.23

Mostyn showed little interest in politics, but considerations of family honour probably obliged him to stand for the knighthood of the shire in December 1620, the first possible opportunity after his succession to the family estates. While apparently returned unopposed for Flintshire, his brother-in-law Sir Richard Wynn was challenged for the Caernarvonshire seat by John Griffith III*. Wynn’s supporters suggested that Mostyn, whose Gloddaith estates gave him considerable influence in the shire, should ‘solicit those that are either neuters, or inclining to the adverse side’, and hoped that his presence at the election would sway some of Griffith’s supporters. However, it was apparently Mostyn who was persuaded to change his mind, backing John Griffith in preference to Griffith Jones of Castellmarch, the compromise candidate put forward by Wynn’s supporters at the last moment when it became clear that they were facing defeat.24 Mostyn left no trace on the comparatively full records of his only Parliament, nor does any of his otherwise copious correspondence with Wynn survive from this period. His apparent inactivity in the Commons can scarcely be ascribed to lack of opportunity. He had a particular grievance against Prince Charles’s Council, which had recently claimed the right of wardship over his Flintshire estates. He was also familiar with the dispute over the will of his relative Sir John Egerton, which he had attempted to arbitrate several years earlier; this comprised one of the impeachment charges brought against Lord Chancellor St. Alban (Sir Francis Bacon*).25

One consequence of Bacon’s fall was the promotion of Wynn’s relative John Williams to the keepership of the great seal. Sir Richard Wynn quickly secured Mostyn’s second son a place in the Williams’s household, for which favour Sir Roger sent Williams two silver flagons. Mostyn was tipped for inclusion on the commission of investigation sent to Ireland in 1622 under (Sir) William Jones I*, but Sir Richard Wynn claimed that his name had been dropped because ‘my lord [keeper] believed the employment would not have pleased him’. Williams apparently wished to gratify Mostyn in order to match his widowed sister with Mostyn’s heir, a plan to which Sir Roger was tactfully but vehemently opposed, ‘by reason (as he said) of the unequality of years between his son and her only, and not out of any other respect at all’; the lady eventually married (Sir) Peter Mutton*.26

Mostyn showed no desire to stand for re-election to Parliament in 1624, when he swiftly pledged his support to his nephew Sir John Hanmer*. This frustrated the Wynns’ plans to promote Mostyn’s heir, Sir Thomas Mostyn, for the Flintshire seat, but Mostyn protested that ‘I may not with my credit leave him [Hanmer] though it were for the dearest I have, having so far engaged my word unto him long since’. Though Wynn had doubtless informed him that Sir Thomas was backed by his father-in-law, justice (Sir) James Whitelocke*, Mostyn claimed that if Whitelocke genuinely agreed, ‘he would have written unto me, or procured a burgess-ship in some other place’.27 Apparently undaunted by this failure, Sir Thomas actually began canvassing for the Flintshire seat in the next general election, in 1625. His ambitions were again frustrated by his father, who, having already agreed to back Sir John Trevor II*, witheringly observed that ‘to make a show to seek it [the county seat] and fail were a greater disgrace than the benefit thereof would be to him that had it’.28

Mostyn was less opposed to the idea of his second son John standing for election in Anglesey, where he held a modest estate in 1624, apparently reasoning that his status as a younger son meant that ‘he hath little to lose, whatsoever fall thereof’. Mostyn wrote a lukewarm letter of recommendation to the local magnate Richard Bulkeley*, with the proviso that ‘if it may not be had without any contesting with any country gentleman, I hold it not worth the having’. The bearer of the letter, Mostyn’s brother-in-law Owen Wynn, carried the day by dint of vigorous canvassing, which intimidated two local candidates, Sir Sackville Trevor* and Rowland Whyte, into withdrawing before the the election.29 Mostyn, who was probably unaware of the circumstances of this return, refused Owen Wynn’s recommendation that John Mostyn should attend the Anglesey assizes in the following summer to offer thanks for his return, ‘in respect that they chose him when they had none other to supply the place’. Feeling slighted, the gentry therefore backed Sir Sackville Trevor at the 1625 election, who ‘resolved to stand for it against all men’. Mostyn, armed with a letter of recommendation from lord keeper Williams, made an inept attempt to lobby Trevor’s son-in-law, Bishop Bayly of Bangor, who apparently convinced Mostyn that his son stood no chance of victory.30 It is unlikely that Mostyn allowed his son to stand in the face of almost certain defeat.

Comparatively little is known about Mostyn’s life after 1627, when Sir John Wynn’s death deprived him of his most regular correspondent. He remained active in local administration, though he was reported to be ‘ancient and not able to travel’ in 1634, and he presumably supported the return of his son John Mostyn for Flintshire at both of the elections of 1640. Ever cautious, he drafted his will on the opening day of the Long Parliament, which recited provisions already made for his wife and younger sons. He died on 18 Aug. 1642, and was buried two weeks later, ‘with great pomp’. He was succeeded by his grandson Sir Roger, an active royalist during the Civil War, who acquired a baronetcy after the Restoration. His descendants regularly represented Flintshire in Parliament until the failure of the male line in 1831.31

Ref Volumes: 1604-1629

Author: Simon Healy


  • 1. C142/368/117; CHES 3/94/16; A.D. Carr, ‘The Mostyn Fam. and Estate, 1200-1642’ (Univ. Wales Ph.D. thesis, 1975), pp. 192-3.
  • 2. J.E. Griffith, Peds. Anglesey and Caern. Fams. 182-3.
  • 3. Al. Ox.; LI Admiss.
  • 4. Carr, 200; Add. 32487/E/3; Griffith, 182-3.
  • 5. Shaw, Knights of Eng. ii. 140.
  • 6. C142/368/117; P. Roberts, Y Cwtta Cyfarwydd ed. D.R. Thomas, 68; NLW, 9056E/822.
  • 7. Roberts, 204.
  • 8. JPs of Wales and Monm. ed. Phillips, 26-30, 100-110.
  • 9. List of Sheriffs comp. A. Hughes (PRO, L. and I. ix), 237.
  • 10. C181/2, ff. 47, 102; SP14/31/1; C212/22/21-3; E179/221/227; 179/264/44; E179/224/598, ff. 2, 5.
  • 11. Eg. 2882, ff. 82v, 162-3.
  • 12. NLW, 6285E, f. 3; HEHL, EL7443.
  • 13. C181/3, f. 129v; 181/4, ff. 95v, 192v; 181/5, f. 185; DCO, Letters and Warrants 1623-6, f. 107; Cal. Wynn Pprs. no. 1545; E178/5886, f. 7; NLW, Bettisfield 1672; C192/1, unfol.; Northants. RO, FH133.
  • 14. Carr, 5-9, 15-47.
  • 15. Ibid. 148, 308-9, 313; UCNW, Mostyn 102; UCNW, Mostyn 6478; NLW, 466E/642.
  • 16. Carr, 200, 335-60, 389-94; UCNW, Mostyn 1; J. Gwynfor Jones, Concepts of Order and Gentility in Wales, 1540-1640, pp. 209-10.
  • 17. Carr, 183, 193-7; UCNW, Mostyn 5486.
  • 18. NLW, 465E/381; Exchequer Proceedings, Jas. I ed. T.I. Jeffreys Jones (Board of Celtic Studs. Hist. and Law ser. xv), 197-8; Carr, 197-8, 243-4; UCNW, Mostyn 871-2, 6935; Cent. Kent. Stud. U269/1/OE818.
  • 19. UCNW, Mostyn 102, 114-16; NLW, 9052E/206; 9053E/479; 9054E/584; 465E/491; Carr, 185-6.
  • 20. NLW, 465E/381; 9052E/269, 288, 290; 9056E/788.
  • 21. NLW, 9055E/746; 9061E/1464 [dated 1613].
  • 22. NLW, 9055E/679; 9056E/820; Roberts, 66; Flint. RO, D/M/573, 3734, 4995.
  • 23. NLW, 9056E/820-2; UCNW, Mostyn 130.
  • 24. NLW, 466E/1000; 9057E/916, 930; CAERNARVONSHIRE.
  • 25. NLW, 9055E/679; 9061E/1458, 1465; R. Zaller, Parl. of 1621, pp. 74-85.
  • 26. NLW, 9057E/960-62; 9058E/1002, 1038; Carr, 328.
  • 27. NLW, 9059E/1177, 1185-7.
  • 28. Procs. 1625, p. 684; NLW, 9060E/1324.
  • 29. UCNW, Mostyn 727, 5484; NLW, 9059E/1172, 1186.
  • 30. NLW, 9059E/1198, 1242, 1324; DWB (Lewis Bayly).
  • 31. Carr, 305, 361; Flint. RO, D/M/3737; Roberts, 204; Mostyn and Glenn, 135-44.