Achaius, King of Scots

The Scottish Renaissance humanist George Buchanan gave a long list of Scottish Kings in his history of Scotland—published in Latin as Rerum Scoticarum Historia in 1582—most of whom are now considered by historians to be figures of legend, or completely misrepresented. The list went back around 1900 years from his time, and began with Fergus I. James VI of Scotland, who was Buchanan's pupil, adopted the story of Fergus I as his ancestor, and the antiquity of the line was emphasised by the House of Stuart.

The genealogy of Scottish kings, going back to Fergus mac Ferchar (i.e. Fergus I) and beyond, was in place by the middle of the 13th century, when it was recited at the 1249 inauguration of Alexander III of Scotland. In 1301 Baldred Bisset was involved in a hearing at the Papal Curia, on the Scottish side of the debate on Edward I of England's claims, and at least helped prepare material dealing with the mythological history that was being adduced as relevant, on both sides.

The question of the antiquity of the Scottish royal lineage, and even the details of the associated origin myth, became particularly significant from 1542 when Mary, Queen of Scots came to the Scottish throne. Buchanan alluded to Mary's long ancestry in his Epithalamium written for her 1559 marriage to Francis II of France. In the period before Mary's betrothal, a marriage to Prince Edward, the future Edward VI of England, was much discussed. As part of that debate, the list of legendary kings of Britain became involved, in the form of the "Brutus myth", promoted by Edward Hall over the doubts of Polydore Vergil. Publicists on the English side of the argument, including John Elder, James Henrisoun, and William Lamb, had cast doubt on the Scottish history.

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