[1] Columba was "of Royal race", the third "lawful son of George de Dunbar, 10th Earl of March"[2] and his spouse Christian née Seton.

[3] On 26 February 1403 (1402/3), while studying at Oxford,[4][5] "Columba son of George de Dunbarre earl of March of Scotland" was granted "the Deanery of the free chapel of St. Mary Magdalene of Bridgnorth" in Shropshire.

More scandalously, in 1410, when a Commission into his activities as Dean was convened, it was found he had stripped lead from the roof of his churches, including that at nearby Quatford, and sold it.

[7] Columba had returned to Scotland, thus evading justice from England,[7] in 1409 and by 1412 he was Dean of Dunbar collegiate church when he witnessed the foundation charter of St Andrews University.

On 1 May 1419, by Papal Dispensation, he was given the additional rectory of the parish church of Locherworth or Borthwick (£30 per annum), from which he was promoted to the post of Archdeacon of Lothian.