The Royal House of Dinefwr was a cadet branch of the Royal House of Gwynedd, founded by King Cadell ap Rhodri (reign 872–909), son of Rhodri the Great. Their ancestor, Cunedda Wledig, born in late Roman Britain, was a Sub-Roman warlord who founded the Kingdom of Gwynedd during the 5th century, following the Anglo-Saxon settlement of Britain. As Celtic Britons, the House of Dinefwr was ruling before the Norman conquest, having to fight with their neighbors such as the Celtics, Anglo-Saxons and Vikings, before struggling with the Normans afterwards. Many members of this family were influential in Welsh history, such as Hywel Dda, who codified Welsh law under his rule, and achieved the important title of King of the Britons, or Lord Rhys, Prince of Wales, who rebelled against Richard the Lionheart, and became one of the most powerful Welsh leaders of the Middle ages.
History
With the death of Rhodri Mawr, the Kingdom of Gwynedd passed to his eldest son Anarawd ap Rhodri. Rhodri's second son Cadell ap Rhodri, however, looked outside Gwynedd's traditional borders and took possession of the Early Medieval Kingdom of Dyfed by the late 9th century, establishing his capital at the citadel of Dinefwr Castle. Cadell ap Rhodri's descendants are designated Dinefwr after the citadel from which they would rule Dyfed.
The Dinefwr dynasty under King Hywel Dda would unite Dyfed and Seisyllwg into the Kingdom of Deheubarth in the early 10th century. During his reign, Hywel Dda would have to submit to the King of the Anglo-Saxons, Edward the Elder, and thereafter support his successor King Æthelstan, the first King of England, and his invasion of Scotland. His legacy would be the codification of Welsh law known as the Laws of Hywel Dda, as he had gathered expert lawyers and priests from all over the country under his leadership for its formation.
The Dinefwrs would rule in Deheubarth until their conquest by the Plantagenet kings in the 13th century. This branch would compete with the House of Aberffraw for supremacy and influence in Wales throughout the 10th, 11th and 12th centuries, with the Kingdom of Powys variously ruled between them. Eventually, a cadet branch of the House of Dinefwr would establish itself in Powys by the mid-11th century, designating themselves as the House of Mathrafal after the castle there named Mathrafal Castle. This dynasty will be the last with a native Welsh Prince of Wales before its annexation into the Kingdom of England.
During the 12th century, Lord Rhys's father, Prince Gruffydd ap Rhys, fought the Normans following the civil war in England and Normandy. This war arose from the rival claims of Stephen of Blois and Empress Matilda to the throne England as descendants of William the Conqueror. From that era, Lord Rhys would end up becoming one of the most successful and powerful Welsh leaders of the Middle Ages, fighting against King Henry Plantagenet as well as against his son, Richard the Lionheart, attacking his Norman lordship and capturing many of his castles. Through Lord Rhys's daughter Gwenllian, wife of Seneschal Ednyfed Fychan, he would also become an ancestor of the House of Tudor, House of Stuart, as well as the current reigning House of Windsor.
Other important members of the Dinefwr family were Sir Rhys ap Gruffydd and Sir Rhys ap Thomas. Sir Rhys ap Gruffydd, a descendant of Ednyfed Fychan, rose to prominence after supporting Hugh Despenser, Earl of Winchester, and Hugh Despenser the Younger, who became the Royal Chamberlain. From supporting the Angevin cause, he would end up becoming the wealthiest and most influential figure among the native Welsh gentry of the 14th century. Thereafter, he was involved in the abdication of Edward II, and joined the new King, Edward of Windsor, fighting for him and Edward the Black Prince at the Battle of Crecy.
One of Rhys ap Gruffydd's descendant, Sir Rhys ap Thomas, would later be instrumental during the War of the Roses, being one of the leader and commander at the Battle of Bosworth Field, alongside the future Tudor King as well as Jasper Tudor, Duke of Bedford, and John de Vere, 13th Earl of Oxford. From that victory, he received lands and positions, such as Privy Councillor, Chamberlain, Justiciar of South Wales and Governor of all Wales. He supported the next King Henry VIII, and joined him and Maximilian I, Holy Roman Emperor, of the House of Habsburg, at the Battle of the Spurs in France. He was also one of the Garter Knights to accompany the King in 1520 at his meeting with Francis I of France at the Field of the Cloth of Gold. He spent his later years at Carew Castle in Wales after receiving the titles of Knight Banneret and Knight of the Garter.