Cadwallon ap Ieuaf (died 986) was a

King of Gwynedd This is a list of the rulers of the Kingdom of Gwynedd. Many of them were also acclaimed "King of the Britons" or "Prince of Wales". List of kings or princes of Gwynedd House of Cunedda * Cunedda (Cunedda the Imperator) (c. 450 – c. 46 ...

from 985 to 986, inheriting the Kingdom of Gwynedd after the death of his older brother

Hywel ap Ieuaf Hywel ap Ieuaf (died 985) was a King of Gwynedd in North West Wales from 979 to 985. Hywel was the son of Ieuaf who had ruled Gwynedd jointly with his brother Iago ab Idwal until 969. In that year the sons of Idwal quarrelled and Iago took ...

in 985. Cadwallon was the son of Ieuaf ap Idwal, son of King

Idwal Foel Idwal Foele (Idwal the Bald) (died c. 942) or Idwal ab Anarawd (Idwal son of Anarawd) was a 10th-century King of Gwynedd in Wales. A member of the House of Aberffraw, he inherited the throne from his father, Anarawd ap Rhodri. William of Malmesb ...

(Idwal the Bald), who had become King of Gwynedd from 916 on the death of his father

Anarawd ap Rhodri Anarawd ap Rhodri () was List of rulers of Gwynedd, King of Gwynedd from 878 to 916. He faced challenges from the Mercia, kingdom of Mercia and Vikings, Viking raiders during a period of uncertainty for his realm. Nonetheless, he managed to sec ...

. Cadwallon's paternal great grandparents were

Rhodri Mawr Rhodri ap Merfyn, commonly known as , was a Welsh king whose legacy has impacted the history of Wales. Rhodri rose to power during a tumultuous era, where the fate of Welsh kingdoms was often determined by the power of their leaders. Early life ...

, King of Gwynedd and Angharad ferch Meurig of Ceredigion.Pierce, T. J., (1959)
IEUAF (or IDWAL) ab IDWAL FOEL (died 985), joint king of Gwynedd
''Dictionary of Welsh Biography''. Retrieved 29 Apr 2025, from https://biography.wales/article/s-IEUA-API-0985 Cadwallon was the younger son of Ieuaf. Upon his grandfather Idwal Foel's death in battle against the

Anglo-Saxons The Anglo-Saxons, in some contexts simply called Saxons or the English, were a Cultural identity, cultural group who spoke Old English and inhabited much of what is now England and south-eastern Scotland in the Early Middle Ages. They traced t ...

in 942, Cadwallon's father Ieuaf and his uncle

Iago ab Idwal Iago ab Idwal (fl. 942-979) was a King of Gwynedd (reigned 950–979) and possibly Powys. Iago was the son of the previous King Idwal Foel who had inherited the throne of Gwynedd on the death of his father Anarawd ap Rhodri in 916. Iago's p ...

were driven from their kingdom by their uncle

Hywel Dda Hywel ap Cadell, commonly known as Hywel Dda, which translates to Howel the Good in English, was a Welsh king who ruled the southern Welsh kingdom of Deheubarth and eventually came to rule most of Wales. He became the sole king of Seisyllw ...

Deheubarth Deheubarth (; , thus 'the South') was a regional name for the Welsh kingdoms, realms of south Wales, particularly as opposed to kingdom of Gwynedd, Gwynedd (Latin: ''Venedotia''). It is now used as a shorthand for the various realms united under ...

, who took the crown for himself. The brothers later reclaimed their inheritance in 950 after Hywel's death. They ruled Gwynedd jointly until 969 when the two brothers quarrelled and Iago took Ieuaf prisoner. Some sources claim Iago had Ieuaf hanged, others that Ieuaf was imprisoned until 988. Cadwallon's uncle Iago then ruled most of another decade. In 974, Cadwallon's brother

raised an army and managed to depose and temporarily drive his uncle Iago from Gwynedd. Iago later returned to the throne for a short time.Pierce, T. J., (1959)
HYWEL ap IEUAF (died 985), king of Gwynedd
''Dictionary of Welsh Biography''. Retrieved 29 Apr 2025, from https://biography.wales/article/s-HYWE-API-0985 In 978 Hywel made another attempt to take the kingdom from Iago, and raided the monastery at Clynnog Fawr, assisted by English troops, possibly provided by Ælfhere,

Earl of Mercia Earl of Mercia was a title in the late Anglo-Saxon, Anglo-Danish, and early Anglo-Norman period in England. During this period the earldom covered the lands of the old Kingdom of Mercia in the English Midlands. First governed by ealdormen under ...

. Hywel defeated Iago in battle in 979, and the same year Iago was captured by a force of

Vikings Vikings were seafaring people originally from Scandinavia (present-day Denmark, Norway, and Sweden), who from the late 8th to the late 11th centuries raided, pirated, traded, and settled throughout parts of Europe.Roesdahl, pp. 9� ...

, possibly in Hywel's pay, and Iago disappears from the historical record. There appear to be no surviving record of Iago's fate, but his son Custennin Ddu was killed whilst raiding the Llŷn peninsula and Anglesey in 980 in conjunction with the

Viking Vikings were seafaring people originally from Scandinavia (present-day Denmark, Norway, and Sweden), who from the late 8th to the late 11th centuries raided, pirated, traded, and settled throughout parts of Europe.Roesdahl, pp. 9� ...

chief Gofraid mac Arailt, king of Man. Hywel made an alliance with the Saxon Ælfhere and attacked

Brycheiniog Brycheiniog was an independent kingdom in South Wales in the Early Middle Ages. It often acted as a buffer state between England to the east and the south Welsh kingdom of Deheubarth to the west. It was conquered and pacified by the Normans ...

and Morgannwg with some success, but 985 his English allies turned on him and killed him. Cadwallon succeeded to the throne of Gwynedd on the death of his brother

in 985. He only reigned for a year, for in 986 Maredudd ab Owain of

invaded Gwynedd, slew Cadwallon and annexed his kingdom.Pierce, T. J., (1959)
MAREDUDD ab OWAIN ap HYWEL DDA (died 999), king of Deheubarth
''Dictionary of Welsh Biography''. Retrieved 29 Apr 2025, from https://biography.wales/article/s-MARE-ABO-0999 This was inherited by Maredudd's grandson by his daughter Angharad, Gruffudd ap Llywellyn who became

King of Wales Latin versions of "King of Wales" () were titles used on a handful of occasions in the Middle Ages. They were very rarely claimed or applied by contemporaries, because Wales in the Middle Ages, Wales, much like Gaelic Ireland, Ireland, usually h ...

References

{{DEFAULTSORT:Cadwallon Ab Ieuaf Cadwallon ab Ieuaf, Prince of Gwynedd Monarchs of Gwynedd 10th-century Welsh monarchs Year of birth unknown