Son of Cleddyf Cyfwlch and brother of Cyfwlch and Bwlch. Syfwlch was one of Arthur’s warriors. He had a sword named Gleisyad, a dog named Cabal, a horse named Llwyrddyddwg, a wife named Diasbad, a grandchild named Eissywed, a daughter named Gwaethaf Oll, and a maid named Gwaeddan. He was needed by Culhwch, as one of his tasks, to help hunt the boar Twrch Trwyth.