Gwladus Ddu, Gladys Dhu ("Gwladus the Dark"), full name Gwladus ferch Llywelyn (died 1251) was a Welsh princess who was a daughter of Llywelyn the Great of Gwynedd and was married to two Marcher lords. Sources differ as to whether Gwladus was Llywelyn's legitimate daughter by his wife Joan or an illegitimate daughter by Tangwystl Goch. However, it is more than likely she was the daughter of Joan, as some sources say that Joan gave her lands to Gwladus. Wikipedia
The definitive Wikipedia entry for Gwladus Ddu. Wikipedia is the biggest multilingual free-content encyclopedia on the Internet. en.wikipedia.org/wiki/Gwladus_Ddu
