sentences:  There is no reason to suppose that every part of Wales was part of kingdom even as late as 700.Dyfed is the same land of the Demetae shown on Ptolemy's map c. 150 during the Roman era.The fourth century arrival of Irish settlers intertwined the royal genealogies of Wales and Ireland, with Dyfed's rulers appearing in "The Expulsion of the Déisi", Harleian MS. 5389 and "Jesus College MS. 20".