Gwladus Ddu

Gwladus Ddu, ("Gwladus the Dark Eyes"), full name Gwladus ferch Llywelyn (died 1251) was a member of the Royal House of Gwynedd. She was a daughter of Llywelyn the Great of Gwynedd and probably Joan Plantagenet, Lady of Wales, the only known illegitemate daughter of John, King of England. Gwladus Ddu married two Marcher lords.

Sources differ as to whether Gwladus was Llywelyn's legitimate daughter by his wife Joan or an illegitimate daughter by his longterm mistress Tangwystl Goch, daughter of Llywarch Goch and whilst she is widely regarded to be the daughter of Joan, this may be problematic when considering the date of Llywelyn and Joan’s marriage (around 1204-05) and the date of Gwladus’ first marriage (1215). Gwladus is recorded in Brut y Tywysogion as having died at Windsor in 1251.