East elevation of house at Plas Mostyn, Brymbo

East elevation of house at Plas Mostyn, Brymbo. Crown copyright: Royal Commission on the Ancient and Historical Monuments of Wales; used with permission

The building shown on the right was once the largest house in Brymbo. This is Plas Mostyn, built sometime in the early 17th century and pictured in a state of dereliction after the Second World War – probably on a bright, windy summer morning, judging by the photograph. Although there is still a farm of the same name, the house itself was demolished not long after this photograph was taken and today there is a cowshed on the site.

Nobody seems to have been able to establish exactly who built Plas Mostyn, which stood on a hilltop in the south of the township. It was a fine double-pile house of three stories, built from narrow slabs of shale stone: originally there were four chimneys, one at each corner of the building. The earliest record of the house and its estate was uncovered by Alfred Palmer, who said that though he was unable to trace it in Norden’s 1620 survey, found it had been sold by a William Santhey to William Mostyn sometime around 1640: it was soon to become known as Plas Mostyn (“Mostyn’s Hall”, more or less). This name still appears on today’s maps.

The obscure Santhey was – perhaps – a member of a landowning family of the same name from Burton, on the other side of Wrexham (since first writing this article I have had to revise this opinion). Mostyn, however, was a rather more public figure, being the third son of Sir Roger Mostyn (1560 – 1642) of Mostyn in Flintshire. In an age when inheritance opportunities for younger sons were rather limited, William had gone into the church, becoming rector of Christleton in Cheshire, and later the archdeacon of Bangor. Career path settled, all that remained for him was to marry an heiress, which he duly did in 1637, marrying Elizabeth Aldersey, daughter of a gentleman of Chester. (Rough portraits of both William and Elizabeth can be still be seen in Whitford church, where she is buried; the links will take you to the site of a church photographer on Flickr).

Whoever it was built for, Plas Mostyn was a handsome house – very suitable for an ambitious ecclesiastic. During the hearth tax assessments of the 1660s it appears to have been assessed as the biggest in Brymbo, at least until Mostyn’s near neighbours, the Griffiths, extended their old seat on the Brymbo estate. Edward Lhuyd, in his 1699 collection Parochialia, ranks the Mostyn property about 14th among the parish’s “houses of note” (he refers to it as “Brymbo Hall”, though this may not be an error as the Griffith house, ranked 2nd in the parish after Acton, is  simply referred to as “Brymbo”). Unfortunately, Plas Mostyn’s unknown designer failed to take account of the effects of gravity, poor foundations, and siting the house on a hilltop, because not long after its construction the walls began to lean and bulge alarmingly. His solution was to add crude, heavy buttresses to the walls, although the ones to the front were later incorporated into a large porch. The house was to remain in substantially the same form, the walls periodically tilting a little further, for the next 300 years. There was a story told by its later owners that Oliver Cromwell once stayed there, although Mostyn’s only contribution to the wars of the period was to complain bitterly to Sir Richard Wynn when asked, like many landowners, to provide a horse and equipment for the King’s forces.

Elizabeth Mostyn died in 1647 after having several children, some of whom are shown on her memorial. William married again shortly after: his new wife, Ann Lewis, was also an heiress – this time to property in Anglesey – and they had six more children (several of whom went on to start families in Anglesey). William Mostyn died sometime between 1669 and 1672 was buried at Wrexham, though his memorial inscription was later entirely defaced “by some mischance” according to an account written in 1720.

The next inhabitant of Plas Mostyn was Roger, eldest son of William’s marriage to Elizabeth Aldersey. Rather than following his father into the church, Roger Mostyn chose to settle down on his estates: in 1679 he married Susan Goodman, a widow from Ruthin. They must have spent much of their time there, as Mostyn was made a burgess of the town in 1687, and served as High Sherriff of Denbighshire in 1689. They had three children, Sidney, Roger and William, all of whom died young.

The Flintshire Mostyns had been amongst the earliest landowners to realise the profitability of coal mining, and their mines had been the most important in Wales throughout much of the 17th century. In the 1680s Roger seems to have made an effort to break into the family business, as he struck an agreement with Sir Thomas Grosvenor, owner of the mineral rights, to dig for coal on the common at Coedpoeth in return for an eighth share of the output. A colliery was certainly in operation there within a few years, and in the coming decades a series of small coal-pits were to appear on the hillsides between the Talwrn and Plas Mostyn itself. Here you can see, on a small scale, the kind of shift in the use of land and resources that would utterly change the economy of Wales, and Britain as a whole, during the next century and a half. As even small landowners like Mostyn realised the greater profitable potential of the minerals under their land rather than the crops and livestock that could be supported on them, the labourers and tenants who had scratched out a living working for them began to shift to better-paid, but far less pleasant, work in mining and quarrying. In the case of Plas Mostyn, the estate became the centre of a landscape that began to be as much industrial as agricultural.

Roger Mostyn himself died, aged 73, in 1712. His memorial in Ruthin church, in which his wife oddly commemorates him side-by-side with her earlier husband (shades of Mrs Ogmore-Pritchard) describes him as a “worthy person” and daily churchgoer, with long service as a “publick magistrate”. None of the extended Mostyn family seem to have lived in Plas Mostyn afterward, which became a tenanted farmhouse for much of the next two hundred years.

You can find more about the history of this house in part 2.