son of Ethwin, was raised to the crown of Scotland, A.D. 788. The emperor Charlemagne sent an embassy to this prince, to request an alliance with him against the English, whose pirates so infested the seas, that the merchants could not carry on their trade. The alliance was concluded in France, upon conditions so advantageous to the Scots, that Achaius, to perpetuate the memory of it, added to the arms of Scotland a double field sowed with lilies. He died in 819.