Gwenllian ferch Gruffydd (Gwenllian, daughter of Gruffydd) (c. 1097–1136) was Princess-consort of Deheubarth in Wales, and married to Gruffydd ap Rhys, Prince of Deheubarth. Gwenllian was the daughter of Gruffydd ap Cynan (1055–1137), Prince of Gwynedd, and a member of the princely Aberffraw family of Gwynedd. Gwenllian was the sister of Prince Owain Gwynedd (died 1170). Gwenllian's "patriotic revolt" and subsequent death in battle at Kidwelly Castle contributed to the Great Revolt of 1136.
There are several notable artistic depictions of Gwenllian. She is often confused with Gwenllian ferch Llywelyn, who lived two centuries later.
Read more about Gwenllian Ferch Gruffydd: Early Life, The Great Revolt 1136, Gwenllian's Legacy, Authorship of The Mabinogi, Hollywood Interpretation, Sources