One of the earliest surviving Welsh texts, Y Gododdin, describes a war raid on the Angles. 300 warriors under Mynyddog Mwynfawr feasted for a year, fell on an overwhelmingly superior army of Angles near the Pennines, and were slaughtered.
But here's the thing. You're probably imagining this war band riding out from a mountain eyrie like Snowdownia. I did when I first heard of it. But no! The first Welsh text was written by a man called Aneirin from Din Eidyn. Din Eidyn is better known today as Edinburgh. Today Aneirin would be considered a Scot!
But there was no such thing as Scotland in those days. Up to the middle of the 7th century, the Ancient Britons were the dominant culture in what is now Southern Scotland. The language that most closely matches their old Brythonic tounge is not Scots, Gaelic, or English, but modern-day Welsh. It is found in place names like Penicuik, Lanark, Penrith, Glasgow, Cramond, Caerlaverock, Traquhair, or Carlisle.
The story of Scotland is sometimes told as a cultural battle between two opposing factions, the English-speaking Lowlands and the Gaelic-speaking Highlands. Told like this, other stories are silenced. The Vikings of the islands. The Picts north of the Forth. But the most forgotten voice is an Old Welsh one. It is the voice of the Lowlands before the Angles came.
Glasgow Cathedral: founded by a 'Welshman'.
Yet the stories are arguably the most colourful in the whole legendary history of Britain, able to stand comparison with the rich lore of old Ireland. Old King Cole? Arthur and Merlin? The Three Futile Battles of Britain? The Praise of Urien and the Excoration of Maelgwn? These are the stories of what is now Southern Scotland and the English border. The three great named early writers were Aneirin, Taliesin, Gildas, who came from Edinburgh, Carlisle, and Dumbarton.
You will struggle to find Scots aware of any of these stories except perhaps the later, medieval retellings of Arthurian legend which relocate the action to the West Country. But if you are Scottish (or indeed English), these stories of the native Britons are as much your heritage as they are of the people of Wales...