Elidir Ddu (fl. 1302-1326) was the son of Elidir ap Rhys of Crug, Wales. He was the father of Philip and grandfather of Nicholas ap Philip ap Syr Elidir Ddu. Nicholas married Sioned, daughter of Gruffydd ap Llwelyn Foethus of Llangathen and became the father of Gruffydd ap Nicholas who became a powerful Welsh nobleman. He was married three times and became the father of eleven children, several of whom also rose to prominence. One of his grandchildren was Sir Rhys ap Thomas (d. 1525) who was important during the Wars of the Roses and then alligned himself with Henry VII, a fellow Welshman.