The purpose of this post is to show how the lordship of Mawddwy had  
descended to Elizabeth Burgh nee "Mouthe", as to which we have the authority of  
Camden in his "Britannia", as follows:-

"Eastward where Dovy runneth standeth Mouthwy a Commot very well knowne,  
which fell for "a childes part of inheritance to William alias Wilcock of  
Mouthwy, a younger sonne of "Gruffith Ap Gwenwynwin Lord of Powis, and by his  sons
daughter it came unto Sir Hugh "Burgh, and by his sons daughters likewise  
unto the familes of Newport, Leighton, Lingein, "and Mitton, of especiall  
respect in these parts."
Interestingly, the 1623 Visitation of Shropshire, prepared under Camden's  
supervision as Clarenceux King of Arms, sets out the same descent at page  104.

However (though not without trepidation) I suggest, on the evidence set  out
below, that the august Camden erred in one minor detail: he should  I believe
have said "and by his grandson's daughter".

Here is my reconstruction of the true descent.

.
1. Owain Cyfeiliog, Prince of Southern Powys 1160-1195 (abdicated), d.  1197
 =Gwenllian verch Owain Gwynedd, Prince of N.Wales. See Welsh  DNB
Owain's biog. in the Welsh DNB

2.Gwenwynwyn ap Owain Cyfeiliog, Prince of Southern Powys 1195-1216 (see  the
Welsh DNB) = Margaret  
[1623 Vis of Salop says she was  Margaret verch Rhys ap Theodor, Prince of
South Wales]

3.Gruffyd ap Gwenwynwyn/ Wenunwyn, Lord of Arwystli, Cyfeiliog  and  Mawddwy:
suit with Llewelyn, Prince of Wales C47/27/2/19 May 19 1280.  Biography
available on line at the National Library of Wales and the DNB. His  complex
involvement with Prince Llewelyn is described in Llewelyn's  biography in the Welsh
DNB.
d. 21 Feb 1286/7 = Hawise Le Strange,  sister of Roger Le Strange SC8/74/3694
Note Edw I granted Church Stretton to  Hawise in 1276 SC8/197/9836. In 1299
she was to be tried for  trespass committed by her and her sons William, John
and Griffin against  Roger Trumwyne and his wife Joan. There is more about this
dispute, which  concerned the castle of la Pole, in CPR 1299, p464. CPR 1322
shows that  this Joan was the former wife of Owen de la Pole, and held land in
Powys as  dower

In 1309 Hawise was given licence to exchange her interest in Stretton with  
the Earl of Arundel for a life interest in his manors of Wroxeter and  Upton,
Salop: CPR 26th October

4. Owen ap Gruffyd, Prince of Powys  Gwenwynwyn [IPM 21 Edw I, C133/64/16]
=Joanna Corbet, d. of Robert Corbet and Eliz le Strange [some sources  say
she was named Margaret, but at any rate his widow was named Joan- see  below
under 1295].
In 1294 custody of his castle of  Welshpool  ("la Pole") was given to Roger
Le Strange by reason of the minority of the  heir- presumably Griffith ap Owen
de la Pole- see below: CPR Sept 28th.
In 1295 a commission issued to John de Havering, Bogo de Knovill and  William
de Mortuo Mari [Mortimer], on complaint by Joan, late the wife of  Owen de la
Pole, that William son of Griffin de la Pole, John and David his  brothers,
Madoc ab Mayler and Owen le Say deforce her of her reasonable dower in  the
lands of  her late husband in Mayrdekerist in Mancho,
sc Mawddwy] Creynon [sc Caereneon] , Bynweythan, Lestynwonnan [part of  
John's portion, v. inf],Tlilangadeuen, Blanto, Cortaloc, Pennarth, Ruthyrgarth,  
Estredaluedan and Trevelyk in Wales;.....  and the sheriff of Salop,  the king's
bailiffs of Monte Gomeri, the bailiffs
of Edmund de Mortuo  Mari in Kery and  Keclewynk, the bailiffs of Richard son
of Alan, earl of  Arundell, in Clonne, and the bailiffs of the bishop of
Hereford in the town  of Bishop's Castle are commanded to provide a jury.

Younger sons of Gruffyd were Llewelyn of Rhayadr and Mochain, John of  
Caereneon, William of Mawddwy, Gruffyd of Stradmarchel and David of  Caereneon.
Presumably William, John and David were the subject of  Joan's complaint, made in
1295- v. supra.

Owen carved up the ancient principality of Southern Powys, dividing it  
between himself and his younger brothers, apparently giving effect to a  
disposition previously made by his father. His brother William's share was "the  land of
Mouthoe", subject to homage, fealty, war service, tallage and castle  repair
costs: I have set out all that I can find about the carve-up in the  footnote
to this post, which I have derived, with due acknowledgments to  Professor
Boynton of the University of Iowa, from a later exemplification at CPR  1342 pp.
496 et seq. The exemplification dates the enrolment of the relevant  documents
to 1300 (18 Edw I), so clearly they were not enrolled for several  years
after Owen's death.

 Owen's son and heir Griffith ap Owen de la Pole prayed for his lands,  with
reference to Powis Castle,
Welshpool SC 8/280/13997. He  d.  1309 (CPR 6th Aug 1309, dealing with the
marriage of his widow  Ela)
Said to have married Ela de Audley of Brimpsfield-  dsp,  since his sister
Hawise "Gadarn"- "the Hardy" became Owen ap Gruffyd's sole  heir, marrying John
Cherleton in 1309, carrying to him the lordship  of Powis: see her entry in
the Welsh DNB

5.. Owen's younger brother Sir William "Wilcox" de la Pole, Lord  Mawddwy  d.
<1302

6. His son Griffin de la Pole did homage and fealty, seemingly while still  
under age, on 20th July 1302: CPR 5th March 1344, a  subsequent
exemplification, which also records that on 11 March 33 Edw I  the Lady Wladusa, late the
wife of Sir William de la Pole, who was dowered  out of her husband's lands in
Powys and held two other thirds in her  custody during the nonage of the heir,
made oath of fealty and was enjoined not  to remarry without the Prince's
licence on pain of forfeiture. I know  nothing more of this lady. but she must I
think have been the second wife  of Sir William, since most sources give Sir
William's wife, mother of his  son Griffin, as Elynor, sister of Owain
Glendower's mother Elen.

Griffin, son of William, petitioned for the land of Mawddwy/Mouthe,  alleging
that his father William held Mawddwy as one of the parceners of  Powys SC
8/258/12897 (circa 1316 according to the National Archives, but it  was probably
much earlier, since he had done fealty and homage in 1302-  v.sup)
Pardoned November 6th 1313 for besieging la Pole, then held by John  Cherleton
Disseised of Deuddyr and Mechain le Coed by John Cherleton in 1328  SC
8/261/13027 and see CPR for 1331. He seems to have recovered the commote  of
Deuddyr, for in 1332 he had royal licence to settle it on  himself, remainder to
Richard, Earl of Arundel.
In 1343 John Cherleton  the elder was detaining Griffin's wife Matilda at la
Pole castle: a commission  was appointed to secure her release on 6th November
[CPR]. I do not know  who this Matilda was.

7. John, Lord Mawddwy, disseised of Shropshire manors by Isolde, widow  of
Sir John de More (petition SC8/221/11030, date 1390) and d.3 Nov 1403.  Married
Elizabeth, daughter and sole heiress of Sir Fulke Corbet, King's  Knight to
Ric II. I have seen no record of his having been the son of  Griffin ap William
ap Griffin, but clearly he must have been heir in tail  of Mawddwy, since
William was heir in tail of the Mawddwy lordship, and not the  son but rather the
grandson of William.

8. John's son and heir Fulke Mouthe, ward of Joan Queen of England 1st  Dec
1403 SC8/229/11446, CPR 1401-5,332. Proved his age 13 H IV

9. John's daughter, Fulke's sister Elizabeth, wife of Hugh Burgh, aged 24  in
1414

It seems that Camden nodded in placing the unnamed father in law of Hugh  
Burgh as the son of William: if he were, he would have been aged 100 or so at  
his death in 1403. Instead I believe him to have been the son of William's son  
Griffin.

FOOTNOTE as to the division of Southern Powys between the six sons of  
Griffin ap Gwenwynwyn