In 240 the Irish king Cormac MacAirt invaded Britain and assumed a nominal sovereignty over it. It was probably about this time that the Irish Gaels effected a lodgment on the coast of Wales and occupied Anglesey and all the northern fringe of the fair lands by the sea and the whole of Southern Wales. That they were in the land we know, not only from the testimony of Welsh ancient writers, but from the number of inscribed stones they have left behind them, some with the Ogam script, bearing distinctly Irish names. All these inscribed stones belong to the period after the occupation from Ireland, and none go back to an earlier date, and give any grounds for supposing that the original population of North and South Wales were Gaels. The Scots or Irish held these parts till an event took place which led to their expulsion. The incursions of the Picts had made residence in the land between the Roman walls, _i.e._ from the Clyde to Solway Firth, altogether unendurable, and a chief there named Cunedda, with his sons and a great host of followers, descended on North Wales to wrest it from the Irish. This they succeeded in doing. Cunedda and his sons were Brittons. After a series of contests they drove the Irish first out of Gwynedd, and then out of Anglesey. Finally they turned them bag and baggage out of South Wales as well. Thenceforth the Gaels never again obtained a foothold for any length of time in Wales. Ceredig, son of Cunedda, gave his name to Ceredigion or Cardigan; Meirion, grandson of Cunedda, has bequeathed his to Merioneth. The contest began between 400 and 450, and the complete sweeping out of the Gael was not accomplished till the beginning of the following century. But by this time the invasion of Britain by the Jute, Angle, and Saxon had begun on a large scale, and as the Teutonic warriors advanced, burning and slaying, they rolled back the unfortunate Brittons westward. After the whole of Eastern Britain had been taken and occupied, the line of demarcation between Celt and Teuton ran from the Firth of Forth along the backbone of the Pennine Range to the Forest of Arden, and thence to Salisbury and to the sea by Christchurch. But the invaders pressed on. In 577 the Brittons were defeated at Deorham, near Bath, and those of Wales were cut off from their brethren in Devon and Cornwall. In 607 they met with a signal reverse at Chester, and they thenceforth were separated from the Brittons in Strathclyde. Still the unsatiated Anglo-Saxons pressed on, and the Brittons finally retained only the mountains of Wales as their last refuge. Many, indeed, fled over the sea and occupied and colonised Armorica, to which they gave the name of Lesser Britain or Brittany.