Arianrhod ("silver wheel") is a figure in Welsh mythology who plays her most important role in the Fourth Branch of the Mabinogion. She is the daughter of Dôn and the sister of Gwydion and Gilfaethwy; the Welsh Triads give her father as Beli MawrTriad 35. Bromwich, Trioedd Ynys Prydein, pp. 284–285 In the Mabinogion her uncle Math ap Mathonwy is the King of Gwynedd, and during the course of the story she gives birth to two sons, Dylan Eil Ton and Lleu Llaw Gyffes, through magical means.