Joan was betrothed to Llywelyn the Great in 1204, and the marriage is thought to have taken place in 1205, although some of the annals of the abbey of St Werburgh in Chester say that it occurred in 1204. She and Llywelyn had at least four children together: •
Gwladus Ddu (1206–1251), who married (1)
Reginald de Braose and (2)
Ralph de Mortimer, with whom she had issue. •
Elen ferch Llywelyn (Helen or Ellen) (1207–1253), married (1)
John the Scot, Earl of Chester and (2)
Robert II de Quincy • Susanna, who was sent to England as a hostage in 1228, and possibly married
Máel Coluim II, Earl of Fife in 1230. •
Dafydd ap Llywelyn (–1246) married Isabella de Braose, died at
Abergwyngregyn. Some of Llywelyn's other recorded children may also have been Joan's: •
Angharad ferch Llywelyn • Marared/Margaret (born ) who married (1)
Sir John de Braose (called Tadody), grandson of
William de Braose, 4th Lord of Bramber. She married (2)
Sir Walter de Clifford and had children by both husbands. Joan often mediated between her husband and her father. According to
Brut y Tywysogion (The Chronicle of the Princes), when John was successfully campaigning in North Wales, "Llywelyn, being unable to suffer the king's rage, sent his wife, the king's daughter, to him, by the counsel of his leading men, to seek to make peace with the king on whatever terms he could." and "Princess of Wales".
Adultery At
Easter 1230,
William de Braose, who was Llywelyn's prisoner at the time, was discovered with Joan in Llywelyn's bedchamber. William de Braose was hanged on 2 May 1230, according to local folklore at
Abergwyngregyn; the place was known as Gwern y Grog. A letter from Nicholas, Abbot of Vaudy, suggests that the execution took place at Crogen near
Bala (
crogi means to hang). Joan was placed under
house arrest for twelve months after the incident. She was then, according to the Chronicle of Chester, forgiven by Llywelyn and restored to favour. She may have given birth to a daughter early in 1231. ==Death and burial==