Born: 1173
Died: 11 April 1240. Llywelyn was buried at Conwy where he is commemorated by a statue (right).

Father: Iorwerth Drwyndwn ab Owain Gwynedd
Mother: Marared, daughter of Madog ap Meredudd

Llywelyn acceded as Prince of Gwynedd in 1194.

He was married in 1205 to Joan of England and also associated with Tangwystyl Goch.

Child 1: Gruffydd ap Llywelyn (d 1244)
Child 2: Dafydd, Prince of Gwynedd
Child 3: Helen
= (1) John, Earl of Chester (d 1237 s.p.) = (2) Robert de Quincy (d 1257)
Child 4: Gwladus Ddu
Child 5: Margaret (Marared)
= (1) John de Braose = (2) Walter Clifford (d 1263)
Child 6: Gwenllian (d 1281)
= William de Lacy
Child 7: Susanna
Probably the daughter of Llywelyn who was recorded as marrying Malcolm, Earl of Fife, in 1230 in the Melrose Chronicle. In 1228, in the Patent Roll, King Henry III refers to her as "Susanna, our niece, the daughter of Llywelyn prince of North Wales and Joanna his wife our sister."

The attribution of some of the children to the two mothers is uncertain but Grufydd is known to be Tangwystyl's son and Dafydd, Gwladus, Helen and Susanna are Joan's children.