Penarddun
The daughter or sister of Beli, although usually a daughter of Dôn, who, by Llyr, became the mother of Manawydan fab Llyr, the half-brother of Bendigeid Vran and Branwen, who were Llyr’s children by Iweriadd, and of Nisien and Efnisien, whom she bore to Eurosswyd.
Most sources, however, make Penardun the mother of Bendigeid Vran, Branwan and Manawydan fab Llyr by Llyr, and ignore that god’s association with Iweriadd.
Arthurian sources made Penardun an ancestor of Arthur by way of Bendigeid Vran.