CWGC thanks the Thiepval Database Project for this story. It summarises information held at the Thiepval Visitor Centre.

Duncan was born in Fortingal, Perthshire, one of two children, and only son, of the Rev. John McColl and Jeannie Mary McColl who later lived at of 64 Braid Road, Edinburgh. His father was minister emeritus of the United Free Church.

He was educated at George Watson's College (1907 to 1915) where he proved to be a competent scholar and a good athlete, being captain of the second XV and a member of the XI in 1914.

After leaving school he had intended to study medicine but instead enlisted and received his commission on 30th July 1915. He went to France on 18th September 1916.

Duncan died on 18th October 1916, aged 19, while encouraging and cheering on his men against a fierce counter-attack of the enemy at Snag trench, as part of the larger Battle of Le Transloy. The 5th Camerons overcame heavy shelling and mud to achieve their objective to successfully take and hold the trench, but incurred 67 casualties.

His commanding officer wrote:

"…In the action he showed coolness and enthusiasm and he encouraged his men with spirit and complete disregard of danger…"

He was reported to have been buried on the battlefield but the grave was subsequently lost.

Second Lieutenant, Duncan C Colvin of the 3rd Battalion, attached to 5th Battalion, Cameron Highlanders, has no known grave and is commemorated on panel and Face 15B of the Thiepval memorial in France.