Legendary History Prior to 1st Century BC
Beli Mawr and Llyr Llediath in Welsh Pedigrees
The Bartrum "Welsh Genealogies"
Bartrum's "Pedigrees of the Welsh Tribal Patriarchs"
A study in charting medieval citations
The Evolution of the "Padriarc Brenin" Pedigree
Generational Gaps and the Welsh Laws
Minimum Age for Welsh Kingship in the Eleventh Century
The Lands of the Silures
Catel Durnluc aka Cadell Ddyrnllwg
Ancient Powys
The Royal Family of Powys
The Royal Family of Gwynedd
The 5 Plebian Tribes of Wales
Maxen Wledig of Welsh Legend
Maxen Wledig and the Welsh Genealogies
Anwn Dynod ap Maxen Wledig
Constans I and his 343 Visit to Britain
Glast and the Glastening
Composite Lives of St Beuno
Rethinking the Gwent Pedigrees
The Father of Tewdrig of Gwent
Another Look at Teithfallt of Gwent
Ynyr Gwent and Caradog Freich Fras
Llowarch ap Bran, Lord of Menai
Rulers of Brycheiniog - The Unanswered Questions
Lluan ferch Brychan
The Herbert Family Pedigree
Edwin of Tegeingl and his Family
Angharad, Heiress of Mostyn
Ithel of Bryn in Powys
Idnerth Benfras of Maesbrook
Henry, the Forgotten Son of Cadwgan ap Bleddyn
The Muddled Pedigree of Sir John Wynn of Gwydir
The Mysterious Peverel Family
The Clan of Tudor Trevor
The Other "Sir Roger of Powys"
Ancestry of Ieuaf ap Adda ap Awr of Trevor
The Retaking of Northeast Wales
Hedd Molwynog or Hedd ap Alunog of Llanfair Talhearn
"Meuter Fawr" son of Hedd ap Alunog
The Medieval "redating" of Braint Hir
Aaron Paen ap Y Paen Hen
Welsh Claims to Ceri after 1179
The Battle of Mynydd Carn
Trahaearn ap Caradog of Arwystli
Cadafael Ynfyd of Cydewain
Maredudd ap Robert, Lord of Cedewain
Cadwgan of Nannau
Maredudd ap Owain, King of Deheubarth
What Really Happened in Deheubarth in 1022?
Two Families headed by a Rhydderch ap Iestyn
The Era of Llewelyn ap Seisyll
Cynfyn ap Gwerystan, the Interim King
The Consorts and Children of Gruffudd ap Llewelyn
The 1039 Battle at Rhyd y Groes
The First Wife of Bleddyn ap Cynfyn
Hywel ap Gronwy of Deheubarth
The Brief Life of Gruffudd ap Maredudd
Owain Brogyntyn and his Family
The Other Gwenwynwyn
Eunydd son of Gwenllian
Sandde Hardd of Mortyn
The Floruit of Einion ap Seisyllt
The Enigmatic Elystan Glodrydd
The Unofficial "History" of Elystan of Powys
Cowryd ap Cadfan of Dyffryn Clwyd
Owain ap Cadwgan and Nest ferch Rhys - An Historic Fiction?
The "sons" of Owain ap Cadwgan ap Bleddyn
The Betrayal by Meirion Goch Revisited
Gwyn Ddistain, seneschal for Llewelyn Fawr
The Men of Lleyn - How They Got There
Trahaearn Goch of Lleyn
Einion vs Iestyn ap Gwrgan - The Conquest of Glamorgan
The Royal Family of Glamorgan
Dafydd Goch ap Dafydd - His Real Ancestry
Thomas ap Rhodri - Father of Owain "Lawgoch"
The "Malpas" Family in Cheshire
Einion ap Celynin of Llwydiarth
Marchweithian, Lord of Is Aled, Rhufoniog
Osbwrn Wyddel of Cors Gedol
Bradwen of Llys Bradwen in Meirionydd
Ednowain ap Bradwen
Sorting out the Gwaithfoeds
Three Men called Iorwerth Goch "ap Maredudd"
The Caradog of Gwynedd With 3 Fathers
Who Was Sir Robert Pounderling?
Eidio Wyllt - What Was His Birthname?
The Legendary Kingdom of Seisyllwg
The Royal Family of Ceredigion
Llewelyn ap Hoedliw, Lord of Is Cerdin
The Ancestry of Owain Glyndwr
Welsh Ancestry of the Tudor Dynasty
Gruffudd ap Rhys, the Homeless Prince
The Children of Lord Rhys
Maredudd Gethin ap Lord Rhys
The 'Next Heir' of Morgan of Caerleon
Pedigree of the ancient Lords of Ial
The Shropshire Walcot Family
Pedigree of "Ednowain Bendew II"
Pedigree of Cynddelw Gam

                                         ARWYSTLI DYNASTY [1]
                                               CHART IV
                    975  Gwyn ap Collwyn[2]===dau vz Gwerystan 
                                     l                    ap Gwaethfoed  990
                        1005  Caradog                     CHART II
                     1040  Trahaearn[3]====Nest vz Gruffudd 
                                     l                  ap Llewelyn  1055 
             _______________l______ ____       CHART III
             l                                        l                    
 1065  Ieuan (base son)        1075  Llywarch[4]==Dyddgu vz Idnerth
             l                                        l         ap Cadwgan  1085
 1095  Dafydd                                   l               CHART V            
             l                                        l          
 1125  Dafydd Fychan             1110  Robert==Dyddgu vz Madog
             l                                        l          ap Idnerth  1120
             l                                        l                 CHART V
             l                                        l
  1155  Sian[6]                   1145  Maredudd[5]
            =                                        l
 Iorwerth ap Einion  1140         1180  Dyddgu
         CHART I                                  =
                                          Trahaearn ap Iorwerth  1170
                                                  CHART I
The Charts cross-referenced above can be seen by clicking on the appropriate links which follow the notes below
[1]  This family shares a common ancestor (Tegonwy ap Teon of c. 735) with the Buellt/Fferlys Dynasty and the 2nd Powys Dynasty
[2] The marriage of Gwyn ap Collwyn to an unnamed daughter of Gwerystan made Caradog ap Gwyn a first-cousin to Bleddyn ap Cynfyn ap Gwerystan.  The Brut entry for 1075 calls Trahaearn ap Caradog a cousin of Bleddyn, but their relationship was first-cousin-once-removed. Bartrum infers that Caradog ap Gwyn must have married a daughter of Gwerystan, but the chronology doesn't work.  Nor would it explain how Cynwrig ap Rhiwallon ap Gwyn got his claim to share the kingship with Trahaearn; both men were great-grandsons of Nest ferch Cadell ap Brochwel ap Aeddan
[3] Trahaearn ap Caradog was made King of Powys following the death of Bleddyn in 1075.  It was his maternal descent from Nest ferch Cadell ap Brochwel that gave him a claim to kingship; his marriage to the daughter of Gruffudd ap Llewelyn alone would not have made him eligible. 
[4]  Owain, the eldest son of Trahaearn, inheirited the Arwystli lordship while Llywarch received the lordship of Cydewain
[5]  The Maredudd ap Robert in this chart is NOT the Maredudd ap Robert, Lord of Cydewain who died in 1244.  This Maredudd ap Robert's sons were all illigitimate, and on his death, the lordship of Cydewain went to his nephew, Maredudd ap Robert ap Robert.
[6]  Medieval genealogists misidentified the wife of Iorwerth ap Einion.  She was Sian, daughter of Dafydd Fychan ap Dafydd....but certainly not the man of that name from Bacheldre.  That man was born c. 1300 and the manor of Bacheldre was not in existence in the 12th century, having been built by Cadwaladr ap Meurig about 1260
[1] ABT 2a, 13 & 14 for the ancestry of Trahaearn and of Maredudd ap Robert
[2] Brut y Tywysogyon 1975 for the implied marriage to granddaughter of the former king of Powys
[3] Dwnn ii, 107 for the marriage of Trahaearn to the daughter of King Gruffudd ap Llewelyn
[4] Dwnn ii, 24 for the marriage of Llywarch
[5] ABT 14 for the marriage of Robert ap Llywarch
[6] Dwnn i, 111 & Visitation of Shropshire of 1623 for the marriage of Dyddgu ferch Maredudd
[7] Dwnn i, 274 identifies (somewhat corruptly) the actual Sian ferch Dafydd Fychan that married Iorwerth ap Einion.  Both Iorwerth and his son, Trahaearn, married ladies of the Arwystli dynasty