[3] The Denys family are recorded in ancient Glamorgan charters, the earliest mention being in 1258, when Willelmo le Denys witnessed a charter effecting an exchange by Gilbert de Turberville, Lord of Coity, of lands in Newcastle, Glamorgan, with Margam Abbey.
[6] In 1379, Denys secured the hand in marriage of Margaret Corbet, a Gloucestershire heiress, thereby attaining wealth and influence.
Margaret had been born a triplet in about 1352, and both her brothers had died young in succession, leaving her the sole heir of the large Corbet landholdings in Gloucestershire and elsewhere.
The manors held by Sir Peter Corbet on his death in 1362, which descended to his grandchildren in succession, John, William and Margaret were as follows: Hope-juxta-Caus, Shropshire, a remnant manor from the great Corbet honour, or virtually autonomous lordship established under William I at Caus Castle.
The marriage, like most of the period, is unlikely to have been the result of a romance but rather arranged by some powerful figure at Court who wished to see Denys rise in the world.
Insufficient evidence exists to identify who this patron of Denys might have been, but pure speculation might suggest John of Gaunt.
Denys's career had begun in the service of John of Gaunt, son of King Edward III, who as Duke of Lancaster was Lord of Ogmore Castle, 3 miles SW of Waterton.
Although certainly an insignificant property within his vast holdings, Denys may have made a mark for himself serving at Ogmore and come to the Duke's notice.
In 1382 Denys's subsequent letters of protection were revoked 2 months after issue when Sir John Devereux, Captain of Calais, testified that he had still not crossed the Channel.
In 1384 he enlisted in the army about to sail for Portugal in the company of the Portuguese Chancellor, Fernand, Master of the Order of St. James of the Sword.
An indictment heard before the Court of Kings Bench in 1387 accused 3 persons of holding conventicles at Earlswood in the lordship of Lydney in order to plot the killing of Sir Gilbert Denys and John Poleyn.
The Greyndour clan dominated the sparsely populated and wild area of the Forest of Dean in western Gloucestershire bordering on the Welsh Marches.
The manor of Pucklechurch lies to the immediate north-east of Siston, and was held by the Bishop of Bath & Wells since 1275, when he had received it from Glastonbury Abbey.
A cadet branch of the Denys family became lords of the manor of Pucklechurch, probably in the 16th century, and continuing until the death of William Dennis in 1701, last of the male line.
In 1403 he was appointed by the King as constable of the late Earl of Stafford's Newport Castle, Monmouth, in charge of 80 archers and 40 lances,[10] specifically to resist the rebellion of Glendower.
Oct in the same year the King issued the following order preserved in the Patent Rolls: Commission to Maurice Russell, Gilbert Dynys, John Rolves and John Harsefelde to assemble all the able fencible men, footmen and horsemen, of the hundreds of Barton Regis by Bristol, Hembury, Pokelchurche, Thornbury, Grymboldesasshe, Berkeley and Whiston and bring them sufficiently armed to the town of Chepstowe by Thursday next at the latest to go with the King or his lieutenant to Wales to resist the rebels bringing with them victuals for 4 days and to take horses from those who have them who cannot labour and deliver them to those who can labour but lack horses.
Oct. 1403 Denys and Edward, Lord Charlton were granted full powers to pardon any rebels in the lordships of Usk, Caerleon and Trilleck who submitted to them.
He continued to hold office at Newport as steward and sheriff, possibly owing these appointments to Ann, dowager countess of Stafford and her 3rd.
[12] Margaret Corbet died in 1398,[13] having produced no male heir, only a daughter, Joan, who married Thomas Gamage and was old enough by 1422 to serve as executrix of her father's will.
[24] This was a very significant position of trust assigned to Denys and others as Berkeley died leaving only a daughter and the succession to the vast Berkeley lands, including the castle itself, became a matter of much dispute amongst his possible heirs resulting in a series of feuds which led in 1470 to the last private battle fought on English soil at the Battle of Nibley Green, between Lord William Berkeley and Viscount Lisle, and there followed the longest dispute in English legal history, which did not end until 1609.
The succession was not however easily achieved for in September 1412, their grandson, another William Gamage, assisted by Sir Gilbert Denys, raised "no moderate multitude of armed men" and besieged Coity for a month, trying to oust Lady Joan Verney, wife of Sir Richard Verney and daughter of Margaret de Turberville, who it seems had taken up residence to assert her own claim to Coity in the confusion following Berkerolles's death.
Denys's eldest daughter Joan was the wife of a certain Thomas Gamage, as his will reveals,[29] possibly brother of William.
He requested Margaret Russell to take a vow of chastity if she wished to inherit his moveable goods in addition to her customary dower of 1/3 of his real estate.
She was however remarried within 7 months,[33] possibly under pressure from Sir Edward Stradling of St. Donat's Castle, Glamorgan, who had obtained the wardship of Morys, her son and Denys's heir.
Katherine's mother was Joan, the bastard daughter of Cardinal Henry Beaufort, Bishop of Winchester, and son of John of Gaunt.