A Scottish abbot who flourished about A.D. 600. All that is known of him is found in the “Breviarium Aberdonense” and in the “Book of Deir”, a ninth-century manuscript now in the University Library of Cambridge, but these two accounts do not agree in every particular. He appears to have belonged to the royal family of the Scoti, his father’s name being Cosgrach. Showing signs of a religious vocation he was entrusted at an early age to the care of St. Columba, who trained him and gave him the monastic habit. He accompanied that saint when he visited Aberdour (Aberdeen) in Buchan. The Pietish ruler of that country gave them the site of Deir, fourteen miles farther inland, where they established a monastery, and when St. Columba returned to Iona he left St. Drostan there as abbot of the new foundation. On the death of the Abbot of Dalquhongale (Holywood) some few years later, St. Drostan was chosen to succeed him. Afterwards, feeling called to a life of greater seclusion, he resigned his abbacy, went farther north, and became a hermit at Glenesk. Here his sanctity attracted the poor and needy, and many miracles are ascribed to him, including the restoration of sight to a priest named Symon. After his death his relics were transferred to Arberdour and honourably preserved there. The “Breviary of Aberdeen” celebrates his feast on 15 December. The monastery of Deir, which had fallen into decay, was rebuilt for Cistercian monks in 1213 and so continued until the Reformation.