This Pierce Welsh genealogy is based on my research and the use of Bartrum's Welsh pedigrees to explore the earlier generations. The tribe of Gwenys is descended from Brochwel Ysgythrog, king of Powys in the sixth century. The arms attibuted to Brochwel are the three nags pictured. Lloyd Piers, first cousin of Thomas of Virginia, adopted these arms from his mother who was heiress of Griffith Lloyd. Here is a flag from a St. David's day parade that shows these arms [By Gareth James, CC BY‑SA 2.0].

Capt William Peirce and Thomas Pierce who both lived on Mulberry Island in Virginia are generally considered to be related, although exactly how is not known. I have not been able to find that they were related through the Piers family, although they could have been. Most likely William Peirce's grandfather Piers Reynold of Welshpool, who living in 1535 had connections with Shrewsbury merchants, may have been related to the family of William Peers, Mercer of Shrewsbury, and who was grandfather of Thomas of Virginia. More details of my reasearch are in a manuscript The Possible Welsh Ancestry of Captain William Peirce.

William Peirce's great-grandmother Margaret vch David named her sister Mally in her Welshpool will dated 1540. Reynold ap David ap Griffith was her will administrator and was also the subject of a chancery case concerning property owned by Maly ap [sic] David. The use of the 'ap' in a woman's Welsh name seems odd, but was evidently not unusual. The exact meaning is unclear. Since Maly was an unusual name and Reynold ap David ap Griffith appeared in both the will and chancery case, then almost certainly Maly was the sister mentioned in the will. The chancery case of Maly named Reynold ap David ap Griffithe and his brother Roger as her 'nyghe kynsman'. The page from Bartrum has the genealogy of Reynold and Roger of Burgedin.

The chancery case concerning the property owned in Burgedin by Maly did not indicate that it was a widow's life portion or that it was jointly held with a living or deceased husband or that she was married or a widow. She may have been unmarried. Also, searching in the genealogies did not show any ways she might have been related to Reynold ap David by marriage and it seems more likely she was related by common ancestry.

The fact that the case called Roger and Reynold Mally's kinsman and not brothers probably means that they were not her brothers. She could not have been the sister of their father David ap Griffith since her Margaret and Mally's father was named David. Probably she was related to their mother who was named Marsli, which is a dimunitve for Margaret.

I have made 2 possible genealogies that show how Margaret and Mally might have been related to Reynold and Roger of Burgedin by their mother Marsli. Since Margaret vch David and Marsli vch David had the same name, probably they were not sisters.

One assumes that Margaret and Mally's father was David ap Ieuan ap Dio and that their mother was an unnamed sister of Marsli. The 1546 subsidy list for the hundred of Pole lists for the village of Burgedin Reynald ap David ap Gruffid, Roger ap David ap Gruffid, David ap Gruffid, and Hugh ap David ap Ieuan ap Dio. Possibly Hugh ap David ap Ieuan ap Dio was the brother of Margaret and Maly, since a later chancery case showed that Margarets's grandson disputed land that had been owned by Ieuan ap Dio in the village of Trewern. The will of Margaret vch David mentioned a neice named Margaret who has been placed as a child of Hugh ap David, but without any proof he had a daughter Margaret.

The second genealogy is a more parsimonious tree that does not require adding any people to fit the known facts. It assumes that Margaret vch David was the aunt of Marsli vch David, hence she was the great aunt of Reynold and Roger. This matches the genealogies and the will of Margaret who names a sister Mally and a neice Margaret. The questions about this is whether the ages match the genealogy.

The rough guide to the generations in Bartrums genealogy have the parents of David Goch (and Margaret?) as David LLwyd (12, b. 1400) and Alice f. Gruffud (13, b. 1430). If Margaret vch David was 65 when she died she would have been born 1475. The guide to Bartrun is rough so the ages are possible. The only 2 people in the genealogy who we have a good idea of their age span are Roger ap David (ca. 1510-1586) and Humfrey ap Piers (ca. 1535-1598). In this genealogy they would be second cousins and lived at the same time but one was probably 20-25 years older.

Either of these two genealogiies show how Captain William Peirce and Thomas Pierce would have been distantly related through the marriage of Thomas's uncle Edward to Elizabeth Lloyd.