Iorwerth Drwyndwn
Iorwerth ab Owain Gwynedd( or Iorwerth Drwyndwn meaning" the flat- nosed"), also called Edward( c. 1130 – 1174), was the eldest legitimate son of Owain Gwynedd( the king of Gwynedd) and his first wife Gwladys( Gladys) ferch Llywarch.
He married Marared ferch Madog.
His son,
Llywelyn the Great, eventually united the realm and became known as" Llywelyn Fawr" and is one of Wales's most famous monarchs.
Iorwerth received Nant Conwy as his inheritance from his father, Owain Gwynedd.
However, he did not receive the crown succession, as was the normal tradition, because of his nose defect( his sobriquet' Trwyndwn' means broken- nosed).
Hywel ab Owain Gwynedd
Hywel ab Owain Gwynedd( died 1170), Wales Prince of Gwynedd in 1170, was a Welsh poet and military leader.
Hywel was the son of Owain Gwynedd, prince of Gwynedd, and an Irishwoman named Pyfog.
In recognition of this, he was also known as" Hywel ap Gwyddeles"( Hywel son of the Irishwoman).
Hywel was also known as the Poet Prince for his bardic skills.
Ieuan Ddu ab Dafydd ab Owain
Ieuan Ddu ab Dafydd ab Owain( fl. 1440–1480), was a Welsh poet, also known as Ieuan Dafydd Ddu and Ieuan Dafydd ab Owain.
He resided at or near Aberdare, Glamorganshire, and, being a gentleman of large estate, was a generous patron of the bards.
The first lines of some of his poems are given in Moses Williams's` Repertorium Poeticum,' London, 1726, 8 vo.
Dafydd ab Owain Gwynedd
Dafydd ab Owain Gwynedd (– 1203) was Prince of Gwynedd from 1170 to 1195.
For a time he ruled jointly with his brothers
Maelgwn ab
Owain Gwynedd and Rhodri ab Owain Gwynedd.
Dafydd was the son of Owain Gwynedd by Cristin ferch Goronwy ab Owain (married).
Since Owain and Cristin were first cousins, the marriage was not accepted by the church, which regarded Dafydd as illegitimate.
Dafydd first appears on the scene in 1157 when King Henry II of England invaded Gwynedd.
Dafydd was involved in the skirmish near Basingwerk in which King Henry was nearly killed.
In 1165, he was recorded as having settled in the Vale of Clwyd and as having attacked Tegeingl, gaining much plunder.
Upon the death of Owain Gwynedd in 1170, his sons fell into dispute over lordship of Gwynedd.
Together, Dafydd and Rhodri attacked and killed their brother Hywel ab Owain Gwynedd that same year.
Dafydd drove out Maelgwn in 1173, sending him fleeing to Ireland.
Other brothers, Iorwerth Drwyndwn and Cynan ab Owain Gwynedd, were killed in 1174, removing two more contenders for the throne.
The same year Dafydd captured and imprisoned his brothers Maelgwn (who had returned from Ireland) and Rhodri.
He was now sole ruler of Gwynedd, and that same year he married Emme (or Emme) of Anjou, the half-sister of King Henry II of England, in summer 1174.
Emme was an illegitimate daughter of Geoffrey V, Count of Anjou.
They had four children:
In 1175, Rhodri escaped and attacked his brother, seizing all Gwynedd west of the River Conwy.
Dafydd was able to keep the eastern part, and in 1177, King Henry gave him the manors of Ellesmere and Hales in England.
He had a castle at Rhuddlan where Gerald of Wales spent a night in 1188 on his journey round Wales with Archbishop Baldwin.
"Having crossed the river Conwy, or rather an arm of the sea, under Deganwy, leaving the Cistercian monastery of Conwy on the western bank of the river to our right hand, we arrived at Ruthlan, a noble castle on the river Cloyd, belonging to David, the eldest son of Owen
, where, at the earnest invitation of David himself, we were handsomely entertained that night."
In 1194, Dafydd faced a new threat from his nephew, Llywelyn ap Iorwerth, who defeated him at the battle of Aberconwy with the aid of his cousins, the sons of Cynan ab Owain Gwynedd, drove him from most of his possessions and imprisoned him in 1197.
He was released a year later thanks to the efforts of Hubert Walter, Archbishop of Canterbury.
Dafydd retired to the Kingdom of England, where he died in May 1203.
Emme died in or after 1214, when she disappears from the Pipe Rolls.
Dafydd ap Maredudd ap Tudur
Dafydd ap Maredudd ap Tudur was a Welsh poet in the later 15th century.
Tudur's works include religious poems, and eulogies of Dafydd ab Owain( abbot of Strata Marcella), Dafydd Deuddwr, Hywel Colunwy, and Watcyn ap Tomas ap Rhoser.
Maelgwn ab Owain Gwynedd
Maelgwn ab Owain Gwynedd was a prince of part of Gwynedd.
Little is known about him, but he was the son of Owain Gwynedd and Gwladus ferch Llywarch ap Trahaearn, and therefore full brother to Iorwerth Drwyndwn, the father of Llywelyn the Great.
On the death of Owain Gwynedd in 1170, Maelgwn received Anglesey as his share of the kingdom, but in 1173, his brother Dafydd ab Owain Gwynedd attacked him and forced him to flee to Ireland.
He returned later that same year, but was taken prisoner by Dafydd.
There is no further record of his fate.
Gwilym Rhyfel
Gwilym Rhyfel( fl. 12th century) was a Welsh- language poet and warrior.
Gwilym ’s surviving work are poems of intercession to Dafydd ab Owain Gwynedd.
Gwilym ’s name also comes down through history in the work of Gruffudd ap Gwrgenau and Iorwerth Beli( 14th century) who name Gwilym as one of the four chief poets of his era, alongside Llywarch ap Llywelyn(" Prydydd y Moch"), Cynddelw and Dafydd Benfras.
Owain Gwynedd
Owain ap Gruffudd (23 or 28 November 1170) was King of Gwynedd, North Wales, from 1137 until his death in 1170, succeeding his father Gruffudd ap Cynan.
He was called "Owain the Great" (Welsh: "Owain Mawr") and the first to be styled "Prince of Wales".
He is considered to be the most successful of all the North Welsh princes prior to his grandson, Llywelyn the Great.
He became known as Owain Gwynedd ("Owain of Gwynedd") to distinguish him from the contemporary king of Powys Wenwynwyn, Owain ap Gruffydd
ap Maredudd, who became known as Owain Cyfeiliog.
Iefan ab Owain Gwynedd
Iefan ab Owain Gwynedd was a son of Owain Gwynedd( the king of Gwynedd between 1137 – 1170) and his second wife Cristina ferch Gronw.
He had a daughter named Gwenllian.
Gruffudd ap Cynan ab Owain Gwynedd
Gruffudd ap Cynan ab Owain Gwynedd was the grandson of Owain Gwynedd a famous king of Gwynedd and ruler of most of Wales in the 12th century.
The longer patronymic form of his name is usually used to distinguish him from the earlier and better- known Gruffudd ap Cynan, king of Gwynedd.
He was born c.1150 and died at Aberconwy Abbey in 1200.
He is known to have fought alongside his brother Maredudd against his uncle Hywel in 1170 and later fought on the side of his cousin Llywelyn ab Iorwerth between 1194- 1197 in a campaign to depose another uncle Dafydd.
Gruffudd is known to have had only one son, Hywel ap Gruffudd ap Cynan ab Owain Gwynedd, who is not known to have had any children of his own and died in 1216.

Question: Who is the paternal grandfather of Dafydd Ab Owain Gwynedd?
Answer: Gruffudd ap Cynan