Brychan Brycheiniog was a 5th-century sovereign of the kingdom of Brycheiniog in Mid Wales. Born in Ireland to Prince Anlach and Marchel, he eventually moved to Wales to rule the territory formerly known as Garthmadrun. He is remembered as a legendary figure with complex ancestry, often linked to both Irish and Greek lineages. As a patriarch of a large holy family, he is recognized as a saint and is commemorated in the Catholic and Orthodox traditions.