* Maelgwn ap Rhys ( died 1231 ), who was the eldest son but illegitimate, refused to accept Gruffydd as his father's successor.

Llywelyn's amendment to Welsh law favoring legitimate children in a Church sanctioned marriage mirrored the earlier efforts of the Lord Rhys, Prince of Deheubarth in designating Gruffydd ap Rhys II as his heir over those of his illegitimate eldest son Maelgwn ap Rhys.

Historically, Rhun ap Maelgwn was Maelgwn's son and successor ( though this may be the ' Runo ' Geoffrey refers to ).

The historical Taliesin was actually a contemporary of Maelgwn Gwynedd's son and successor Rhun.

Of those who have promoted a connection, perhaps the most notable person of late is John Morris in his Age of Arthur, where he refers in passing and without authority, to "... Bridei, son of Maelgwn, the mighty king of north Wales, ...".

According to legend Taliesin was adopted as a child by Elffin, the son of Gwyddno Garanhir, and prophesied the death of Maelgwn Gwynedd from the Yellow Plague.

To test Elphin ’ s claims, Maelgwn sent his son Rhun ( who had a reputation of never being turned down by a woman ) to Elphin ’ s house to despoil his wife ’ s virtue.

Cadwallon consistently appears in the genealogies of the Kings of Gwynedd as the son of Cadfan ap Iago and a descendant of Maelgwn Gwynedd and Cunedda.

Maelgwn locks Elffin up and sends his boorish son Rhun to defile Elffin's wife and steal her ring as evidence.

He succeeded his father Rhun ap Maelgwn as king, and was in turn succeeded by his son Iago.

In one passage, Maelgwn Gwynedd sends his son Rhun on a mission to seduce the wife of Elffin ap Gwyddno.

* Maelgwn ab Owain Gwynedd ( died c. 1173 ), son of Owain Gwynedd and ruler of Anglesey

* Maelgwn ap Rhys ( c. 1170-1230 ), son of Rhys ap Gruffydd and ruler of part of Deheubarth

According to Gildas, Cadwallon's son, Maelgwn Gwynedd, murdered his uncle to ascend to the throne, which suggests that someone other than Cadwallon himself inherited the kingdom upon Einion's death.

Maelgwn was the son of Rhys ap Gruffydd ( The Lord Rhys ) by his wife Gwenllian ferch Madog, daughter of Madog ap Maredudd prince of Powys.

His territory passed to his son, Maelgwn ap Maelgwn, called Maelgwn Fychan.

Bridei is suggested to have been the son of Maelgwn Gwynedd by John Morris in his Age of Arthur, where he refers in passing and without authority, to "... Bridei, son of Maelgwn, the mighty king of north Wales, ...".

His elder brother was Maredudd ap Gruffydd, and there were two younger brothers, Morgan and Maelgwn.

Morgan was also killed and Maelgwn captured.

In 1189 Gruffydd persuaded Rhys to imprison Maelgwn, and he was given into Gruffydd's keeping at Dinefwr.

In 1194 Rhys was defeated in battle by Maelgwn and Hywel, who imprisoned him in Nevern castle, though Hywel later released his father without Maelgwn's consent.

Gwynedd was the most powerful of these kingdoms in the 6th century and 7th century, under rulers such as Maelgwn Gwynedd ( died 547 ) and Cadwallon ap Cadfan ( died 634 / 5 ) who in alliance with Penda of Mercia was able to lead his armies as far as Northumbria and control it for a period.

Owain was married twice, first to Gwladus ferch Llywarch ap Trahaearn, by whom he had two sons, Maelgwn ab Owain Gwynedd and Iorwerth Drwyndwn, the father of Llywelyn the Great, then to Cristin, by whom he had three sons including Dafydd ab Owain Gwynedd and Rhodri ab Owain Gwynedd.

King Maelgwn of Gwynedd was still living when Gildas wrote this, therefore Gildas wrote this on or before AD 547.

When King Maelgwn attempted to show the finger to Elffin, he pointed out that his wife cut her fingernails more often than the owner of the finger, had servants to knead dough and never had any under her nails, and her ring was loose on her finger, and that one was tight.

Maelgwn Gwynedd ( died c. 547 ) was King of Gwynedd for an unspecified period in the early 6th century.

More formally his name was Maelgwn ap Cadwallon (), also known as Maelgwn Hir ().

Maelgwn was a generous supporter of Christianity, making donations to found churches throughout Wales, far beyond the bounds of his own kingdom.

Maelgwn was the first king to enjoy the fruits of his family's conquest and he is considered the founder of the medieval kingdom's royal family.

Maelgwn was a generous contributor to the cause of Christianity throughout Wales.

In his 1723 Mona Antiqua Restaurata, Henry Rowlands asserts that Bangor was raised to an episcopal see by Maelgwn in 550, but he provides no source for the assertion.

He says Maelgwn held a regional pre-eminence among the other 4 kings, going on to say that he overthrew his maternal uncle () to gain the throne ; that he had taken up life as a monk but then returned to the secular world ; that he had been married and divorced, then remarried to the widow of his nephew after being responsible for his nephew's death ; and that he was tall.

This was successively softened down into Mailcon or Mailcun, to become Maelgwn.

The Isle of Anglesey was the base of power of the kings of Gwynedd, so describing Maelgwn as the " dragon of the island " is appropriate.

Among its spurious claims it says that Maelgwn Gwynedd came to the crown following Vortiper, that he was succeeded by a certain Caretig, that he was the fourth king of all Britain after Arthur, and that he had two sons, Einion and Rhun.

Saint Cwyllog, daughter of Caw Cawlwyd of Twr Celyn, had been given lands by Maelgwn Gwynedd.

In ' The Three Holy Families of the Isle of Britain ', there is a story of Caw and his children who had been driven from their lands by the Gwyddelian Picts, and who then came to Wales and were given land in Anglesey by Maelgwn.

Deiniol is said to have studied under Cadoc of Llancarfan and to have been later given land, by Maelgwn Gwynedd, to found a monastery on the site where Bangor Cathedral now stands.

In 1192 Rhys secured Maelgwn's release, but by now Maelgwn and Gruffydd were bitter enemies.

He is thus most commonly referenced by appending the name of the kingdom to his own: Maelgwn Gwynedd.

The only contemporary information about the person is provided by Gildas, who includes Maelgwn among the five British kings who he condemns in allegorical terms in his De Excidio et Conquestu Britanniae.

Gildas refers to Maelgwn by the older form of his name, Maglocunus ( or Maglocunos ).

The evidence suggests that Maelgwn held a pre-eminent position over the regions ruled by the descendants of Cunedda, perhaps in the sense of a regional high king.

Taliesin is said to have been dispossessed of his property by Maelgwn, and so cursed him.

* Maelgwn of Gwynedd, described by Gildas as the " dragon of the island "

Maelgwn was curiously described as " the dragon of the island " by Gildas which was possibly a title ( Pendragon?

At his death in 1170, a bloody dispute broke out between his heir Hywel the Poet-Prince and Owain's younger sons Maelgwn, Rhodri, and led by Dafydd, all three the sons of the Princess-Dowager Cristen.

Wortiporius then ruled peacefully for four years, beings succeeded by " Malgo " ( Maelgwn Gwynedd ).

Geoffrey's Malgo is equated with the historical ruler Maelgwn Gwynedd, who was by contrast a powerful king.

There are later stories that add speculations, for example by asserting that Elidyr was contesting Rhun's succession to Maelgwn Gwynedd's throne, but these are nothing more than speculation.