Quartigod-tier son of Pryderi (demigod son of Rhiannon-the-Brittonic-horse-goddess by Pwyll) by Cigfa. Listed among Arthur's warriors in Culhwch ac Olwen as "Hyfaidd Hir mab Pryderi" — the principal continuing-Dyfed-dynastic-line attestation in the Welsh tradition. The continuation of the Pwyll-Rhiannon-Pryderi line through Hyfaidd places the Mabinogion First-Through-Fourth-Branch dynastic structure on the same multi-generation divinity-dilution pattern as the Greek Heraclidae, Hindu Pandavas, Norse Vǫlsungar, and Mesopotamian Uruk dynasty.