Ednyfed Fychan ap Cynfrig (, died 1 October 1246) was a Welsh nobleman who served as or seneschal (roughly equivalent to a modern prime minister) of the Kingdom of Gwynedd in North Wales. Ednyfed held this position under the princes of Gwynedd for almost thirty years, and his tenure as (plural: ) appears to have coincided with the transformation of the office from one of domestic service to that of being the prince of Gwynedd's closest adviser and agent.

From 1217 onwards, Ednyfed is recorded witnessing Llywelyn ab Iorwerth's charters, carrying out diplomatic missions, administering justice, and perhaps even leading military action on the prince's behalf. After Llywelyn's death in 1240, Ednyfed served in the same position under Llywelyn's son and successor Dafydd, and is repeatedly recorded leading diplomatic missions on Dafydd's behalf to his rebellious brother Gruffudd and King Henry III of England. Ednyfed died some eight months after Dafydd, probably on 1 October 1246.

Ednyfed established a ministerial dynasty which served the princes of Gwynedd for over thirty years after his death until the Edwardian conquest. His preeminence allowed him to marry Gwenllian, a daughter of the Lord Rhys, prince of Deheubarth. Ednyfed's sons succeeded him as and his descendants held a monopoly on the position until the final campaign of Llywelyn ap Gruffudd in December 1282, the turning point of Edward I's conquest of Wales. Even after the Conquest, Ednyfed's heirs and the heirs of his brothers, known as the 'descendants of Ednyfed', enjoyed special privileges in their tenure, first granted by the Llywelyns. They held their lands free from all renders other than military service, which allowed them to become very wealthy and influential. Ednyfed was granted land across Wales and many of his descendants served in the new English administration. Ednyfed's grandson Tudur Hen ap Goronwy established the branch of the family associated with Penmynydd in Anglesey, which produced leading ecclesiastical and administrative figures of the fourteenth century in Wales. Owen Tudor, grandfather of Henry VII, was a member of this family, thus making Ednyfed the first distinguished ancestor of the House of Tudor, the house that held the throne of England from 1485 to 1603.

Early life Little is known of Ednyfed's early life beyond his being born into an established family related to the Second Dynasty of Gwynedd. Ednyfed was the eldest son of Cynfrig ab Iorwerth, whose grandfather Gwgon established the settlement of Betws Gwyrion Gwgon in modern Denbighshire. Ednyfed's byname (a soft mutation of the Welsh word , 'small' or 'junior') usually would suggest his father or grandfather was also named Ednyfed, but as this is not the case, it may instead refer to his size. The core territory associated with Ednyfed's family was that around Abergele in Rhos, a cantref of the Perfeddwlad. Ednyfed's mother was Angharad ferch Hwfa from Cyffylliog in Dyffryn Clwyd, whose mother in turn was Gwenllian, daughter of Owain Gwynedd, king of Gwynedd. Ednyfed's family was very influential in Rhos and later generations would claim that Marchudd ap Cynan of was the founder of the family. Sixteenth-century poet and genealogist Gruffudd Hiraethog alleged Marchudd was and to the ninth-century king of Gwynedd Rhodri Mawr, while the seventeenth-century antiquary Robert Vaughan calls him 'Lord of Abergeleu'. This lineage was ultimately traced to one 'Cadrod Calchfynydd', son of Cynwyd Cynwydion, supposed ancestor of the royal dynasty of Strathclyde in the formerly Brittonic-speaking area of northern Britain known as the Old North .

King Henry VII of England, a lineal descendant of Ednyfed, appointed a commission in about 1490 to examine the pedigree of his grandfather Owen Tudor. The original report of this commission does not survive, but its text was printed in William Wynne's 1697 version of David Powel's 1584 Historie of Cambria. This commission recorded that Ednyfed fought against King John during the reign of Llywelyn ab Iorwerth and slew three English lords one morning in battle. According to the story, after Ednyfed showed their heads to Llywelyn, the prince allowed him to bear three bloody heads as his arms in token of his victory, which were also borne by his descendants, including the Penmynydd family.

Welsh historian John Edward Lloyd situated Ednyfed's feat within the context of the invasion of Gwynedd in 1210 led by Ranulf de Blondeville, Earl of Chester, and Peter des Roches, bishop of Winchester. The earl sought to take Perfeddwlad for himself and built castles in Holywell and Degannwy, and in the next year King John himself invaded and ravaged Gwynedd, heading an army with most of the other Welsh princes under him. While this campaign was disastrous for Llywelyn, who only regained his position by 1213, this may have been when Ednyfed first caught the prince's eye and began his long career of service to the princes of Gwynedd. The folk memory of Ednyfed's actions may reflect real events, but the grant of arms "almost certainly [occurred] significantly after his death in 1246", according to historian David Stephenson.

Tenure as Service under Llywelyn ab Iorwerth Ednyfed Fychan is first recorded in Llywelyn ab Iorwerth's service acting as a seneschal or in summer 1217, when he was recorded as heading a witness list in a grant by Llywelyn of Llandimôr in Gower to Morgan Gam of Afan. Ednyfed was preceded in this role by Gwyn ab Ednywain, who was probably first to Gruffudd ap Cynan, ruler of Meirionnydd and Gwynedd Uwch Conwy before being overthrown by Llywelyn in 1199. Gwyn's last recorded action in the role was his heading a list of witnesses confirming a donation of land by Llywelyn to the Cistercian abbey of Strata Marcella on 25 November 1209. According to David Stephenson, Ednyfed was "almost certainly" Gwyn's immediate successor, though it is impossible to date the beginning of Ednyfed's tenure in the office.

In March 1218, Llywelyn ab Iorwerth signed three agreements with Henry III of England, known collectively as the Treaty of Worcester. These confirmed Llywelyn's occupation of Powys and the royal castles of Cardigan and Carmarthen which he had won in the campaigns of 1215–16. However, these agreements also asserted the king's overlordship over Llywelyn and other Welsh lords, who were required to do homage to him. In the third of these agreements, confirming Llywelyn's right to hold the king's court in the royal castles, Ednyfed appears as a negotiator and leads the list of the prince's officials and leading men of the principality who are bound to the terms of the treaty. According to the treaty, Llywelyn's officials and supporters would "be absolved from homage and fealty to [Llywelyn]" should the prince betray the terms of the agreement, and could "[not]... return to Llywelyn's homage and fealty without first making satisfaction to the king or his heirs concerning the aforesaid breaches".

Similarly, Ednyfed appears to have been a chief negotiator in the 1222 talks which led to the marriage of Llywelyn's daughter Helen to John of Scotland, heir apparent to the earldom of Chester. The pair were married "for the purpose of effecting a lasting peace" between Llywelyn and Ranulf de Blondeville, John's uncle, against whom Ednyfed had fought some twelve years earlier yet became the prince's closest ally in England. Perhaps in recognition of his services in upholding the treaty of Worcester, Henry III granted Ednyfed letters of protection in 1229 for some of his holdings: Llansadwrn in Ystrad Tywi, and Cellan and Llanrhystud in Ceredigion.

In 1223, in accordance with the terms of the Treaty of Worcester, Ednyfed acted with the king's authority and as Llywelyn's chief representative, determining the limits of lands won by Maelgwn ap Rhys, Rhys Gryg, and Owain ap Gruffudd of Deheubarth in the campaign of 1215–16. The findings of an inquisition held on 28 October 1278 recorded Ednyfed, "justice of the prince", had arbitrated a land dispute between two lords of Mechain some decades before, which suggests he also held legal authority in Llywelyn's principality. This is further supported by an occasion in 1234 when Ednyfed arbitrated a dispute in the lordship of Madog ap Gruffudd Maelor between the monks of Valle Crucis and the freemen of Llangollen over a dispute about the ownership of a fishing weir on the Dee.

Over Easter 1230, Llywelyn found his wife Joan, legitimised daughter of King John, in compromising circumstances with the marcher lord of Brecon, William de Braose, whom Llywelyn consequently had hanged on 2 May that year. Joan was kept imprisoned by Llywelyn for her infidelity until 1231. The execution of de Braose did not cause an incident with the English, but hostilities between prince and king broke out in April 1231, when Llywelyn attacked de Braose's former castle at Radnor, which was then being managed by the powerful justiciar Hubert de Burgh. The royal counter-campaign of 1231 headed by de Burgh stalled, and de Burgh was removed from his position in 1232. Ednyfed Fychan led a diplomatic mission to Henry III which resulted in a truce between Llywelyn and the king for a year from 30 November 1231. Ednyfed made two further visits in May and November 1232 together with Llywelyn's wife Joan to further negotiate with the king's representatives.

However, in 1233, Llywelyn threw in his lot with Richard Marshal's baronial rebellion against Henry III. While Llywelyn was making gains in this short conflict, he sent Ednyfed and Dafydd ap Llywelyn, his son by Joan, to negotiate terms with the king at Worcester in June 1233. When Richard was murdered by his allies in Ireland in early 1234, Llywelyn sealed a lasting peace with the English Crown in June that year with the Pact of Myddle. Llywelyn appears to have personally negotiated the terms of this treaty enacting a peace between Henry and the prince from 25 July 1234, extending for two years, but which was renewed yearly until Llywelyn's death. No castles could be built or repaired in the whole of the March, and Llywelyn was confirmed in his possession of Buellt and Cardigan. Henry requested Ednyfed be present when extending the truce in 1237, and he appears at the list of the prince's ministers who swore to uphold the truce upon its renewal in 1238. According to Matthew Paris, Llywelyn suffered a massive paralytic stroke in late spring 1237. This led Dafydd to assume effective rulership of Gwynedd.

Because there was peace between Llywelyn and the king after 1234, Ednyfed decided to go on pilgrimage to the Holy Land, and received safe conduct through England from the king in June 1235. Whilst waiting to depart from London that same month, the king ordered Ednyfed be given a silver cup worth five marks. However, this grant was not fulfilled because the King's treasurer did not have the cup. This attests to Ednyfed's importance at the court of Llywelyn, as well as the esteem in which Ednyfed was held by Henry III. There is no further record of the results of Ednyfed's pilgrimage, but he is next recorded being summoned by Henry to negotiate another treaty in 1237, and so historian Kathryn Hurlock argues that Ednyfed completed a crusading tour of the Levant.

Service under Dafydd ap Llywelyn