Rhydderch ab Iestyn
Rhydderch ab Iestyn was king of Deheubarth and controlled the Kingdom of Powys in Wales during the early part of the eleventh century.
Comparatively little has been recorded about Rhydderch ab Iestyn in the annals. When Llywelyn ap Seisyll, king of Gwynedd and Deheubarth, died unexpectedly in 1023, Rhydderch was able to seize Deheubarth, apparently by force of arms, disinheriting Llewellyn's young son Gruffudd. In 1033 Rhydderch is recorded by Brut y Tywysogion as having been slain by the Irish, but with no explanation of the circumstances.
The kingdom of Deheubarth returned to the original dynasty in the form of Hywel ab Edwin and his brother Maredudd. A battle between Hywel and his brother and the sons of Rhydderch is recorded the following year. In 1045 Rhydderch's son Gruffudd ap Rhydderch was able to seize Deheubarth from Gruffudd ap Llywelyn, and he held it for ten years until Gruffudd regained it.
Rhydderch had at least recorded three sons. Gruffudd ap Rhydderch was King of Morgannwg and Deheubarth, and was killed in battle against Gruffudd ap Llywelyn, son of Llywelyn ap Seisyll. Caradog ap Rhydderch was killed by the "Saxons". Rhys ap Rhydderch was put to death at "Bulendun", order of King Edward the Confessor as punishment for his raiding into England, described in the D version of the Anglo-Saxon Chronicle as having done "harmful things". Rhys' head was brought to King Edward on 5 January 1053 at the royal court in Gloucester.