Guest-written Papers
Reference Abbreviations
Guidance Articles for Researchers
Single Family Analysis
Families of Mixed Origin
Family Pedigrees
Mis-identified Same-Named People in Wales
Battles and Historical Events
Ancient Welsh Territories
Welshmen in Llydaw, Brittany
The Men of the North
Legendary History Prior to 1st Century BC
Beli Mawr and Llyr Llediath in Welsh Pedigrees
Papers Related to Maxen Wledig
Bartrum's "Pedigrees of the Welsh Tribal Patriarchs"
Britain's Royal Roman Family
The Royal Family of Powys
2nd Powys Royal Dynasty
The Royal Family of Gwynedd
Men Descended from Tudwal Gloff
Royal Family of Gwent/ Glamorgan
Royal Family of Brycheiniog
15 Noble Tribes of Gwynedd
The 5 Plebian Tribes of Wales
Glast and the Glastening
Papers about Rhiryd Flaidd and Penllyn
The Men of Collwyn ap Tangno of Lleyn
Edwin of Tegeingl and his Family
Ednowain Bendew in Welsh pedigrees
Ithel of Bryn in Powys
Idnerth Benfras of Maesbrook
Tudor Trefor and his Family
Trahaearn ap Caradog of Arwystli
The Family of Trahaearn ap Caradog
Cadafael Ynfyd of Cydewain
Maredudd ap Owain, King of Deheubarth
Sandde Hardd of Mortyn
The Floruit of Einion ap Seisyllt
The 5 Dafydd Llwyds of Llanwrin Parish
Cowryd ap Cadfan of Dyffryn Clwyd
Osbwrn Wyddel of Cors Gedol
Bradwen of Llys Bradwen in Meirionydd
Who Was Sir Robert Pounderling?
Sir Aaron ap Rhys
Eidio Wyllt - What Was His Birthname?
Ifor Bach, Lord of Senghenydd
Ancestors and Children of the Lord Rhys

                                         ARWYSTLI DYNASTY [1]
                                               CHART IV
                    975  Gwyn ap Collwyn[2]===dau vz Gwerystan 
                                     l                    ap Gwaethfoed  990
                        1005  Caradog                     CHART II
                     1035  Trahaearn[3]====Nest vz Gruffudd 
                                     l                  ap Llewelyn  1050 
             _____________l______ ____       CHART III
             l                                          l                    
 1063  Ieuan (base son)        1070  Llywarch[4]==Dyddgu vz Iorwerth
             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]                   1143  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 interim King of Powys following the death of Bleddyn in 1075.  It was his father's maternal descent from Nest ferch Cadell ap Brochwel that gave Trahaearn 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.  See the paper "Maredudd ap Robert, Lord of Cydewain " at the link below:
[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