Born in Montrose in 1906, Thomas Douglas Macdonald was brought up as a member of the Plymouth Brethren. Macdonald trained as a teacher in Aberdeen and took up his first post at the age of 19, as a headmaster in Wester Ross. In 1926 he went to Palestine, where he taught for three years in the United Free Church's College at Safed. Returning to Scotland, he began to turn towards the Catholic faith and studied Gaelic at the University of Glasgow for a year.
Macdonald chose the Gaelic pen name of 'Fionn MacColla', and spent the inter-war years struggling as a writer, publishing his first novel, The Albannach in 1932. And the Cock Crew, which was to become his best-known novel, was not published until 1945. In the following years he continued to work as a head teacher, mostly in the Highlands and Islands, before moving to Edinburgh in 1961. Fragments of another historical novel, set in Reformation times, appeared as 'work-in-progress' under the titles of Scottish Noël (1958) and Ane Tryall of Heretics (1962), before being published (posthumously) as Move Up John in 1994.
MacColla's strong views on Scottish Protestantism received philosophical expression in his study At the Sign of the Clenched Fist (1967), and were rehearsed again in his short autobiography Too Long in this Condition (1975). Despite being hailed by Hugh MacDiarmid as 'intellectually equipped far beyond any of the new Scottish writers', MacColla had found publication difficult after the critical success of And the Cock Crew. A number of manuscripts and fragments were found among his papers after his death in 1975, including a novel in a more optimistic vein written during the 1950s, which was published as The Ministers in 1979.