Gwenllian was the youngest daughter of
Gruffudd ap Cynan, Prince of
Gwynedd, and his wife, Angharad. She was the great-great-great-granddaughter of
Brian Bóruma mac Cennétig,
High King of Ireland. Gwenllian grew to be strikingly beautiful. After
Gruffudd ap Rhys, the
Prince of Deheubarth, ventured to
Gwynedd around 1113 to meet her father, Gwenllian and Deheubarth's prince became romantically involved and
eloped. She married Gruffudd ap Rhys shortly after 1116. Gwenllian and Gruffudd had the following children: • Morgan ap Gruffudd (c. 1116, Carmarthenshire – 1136) • Maelgwn ap Gruffudd (c. 1119, Carmarthenshire – 1136) • Gwladus ferch Gruffudd (between 1120 and 1130, Carmarthenshire – after 25 July 1175) • Nest ferch Gruffudd (between 1120 and 1130, Carmarthenshire – after 25 July 1175) • Owain ap Gruffudd (c. 1126, Carmarthenshire – after 1155) •
Maredudd ap Gruffudd (c. 1130/1, Carmarthenshire – 1155) •
Rhys "Fychan" ap Gruffudd (c. 1132,
Dynevor Castle,
Llandeilo,
Carmarthenshire – after 24 April 1197) • Sion ap Gruffudd (c. 1134, Carmarthenshire – after 1155) Gwenllian joined her husband at his family seat of
Dinefwr in
Deheubarth. Deheubarth was struggling against the
Norman invasion in
South Wales, with
Norman, English, and
Flemish colonists in footholds throughout the country. While the conflict between the Normans and the Welsh continued, the princely family were often displaced, with Gwenllian joining her husband in mountainous and forested strongholds. From here, she and Gruffudd ap Rhys led
retaliatory strikes, aka "lightning raids" against Norman-held positions in Deheubarth. ==Great Revolt 1136==