The chief Roman ruler, at any rate during the later wars against the invaders, was called Dux Britanniae, “the ruler of Britain.” It became the aim of the ablest kings to restore the power of this officer, and to carry on his work, to rule and defend a united country. And I will tell you briefly how the kings ruled and defended Wales for more than five hundred years—how Maelgwn tried to unite it, how Rhodri tried to prevent the attacks of Saxon and Dane, how Howel gave it laws, and how Griffith tried to defend it against England. Between 400 and 450 Rome left Wales to look after itself. An able family, called the House of Cunedda, took the power of the Dux Britanniae, and they translated the title into Gwledig—“the ruler of a _gwlad_ (country).” Of this family Maelgwn Gwynedd is the most famous. It was his work to try to unite all the smaller kings or chiefs of Wales under his own power as “the island dragon.” It was a difficult thing to persuade them; they all wanted to be independent. A legend shows that Maelgwn tried guile as well as force. The kings met him at Aberdovey, and they all sat in their royal chairs on the sands. And Maelgwn said: “Let him be king over all who can sit longest on his chair as the tide comes in.” But he had made his own chair of birds’ wings, and it floated erect when all the other chairs had been thrown down. Before Maelgwn died of the yellow plague in 547, his strong arm had made Wales one united country, and had made every corner of it Christian. The new wave of nations, coming on as surely as the tide, began to beat against Wales. The Picts came from the northern parts of Britain, and Teutonic tribes swarmed across the eastern sea. The Angles came to the Humber, and spread over the plains of the north and the midlands of Roman Britain; the Saxons came to the Thames, and won the plains and the downs of the south-east. In 577 the Saxons, after the battle of Deorham, pierced to the western sea at the mouth of the Severn; they crept up along the valley of the Severn, burning the great Roman towns. Before they reached Chester and the Dee, however, they were defeated at the battle of Fethanlea in 584. But the Angles soon appeared, from the north; and after their victory at Chester in 613, they won the plains right to the Irish Sea.