Background
Moncreiff was born in Edinburgh, the elder son of James Moncreiff, 1st Baron Moncreiff and his wife Isabella Bell, daughter of Robert Bell, Procurator of the Church of Scotland.
Moncreiff was born in Edinburgh, the elder son of James Moncreiff, 1st Baron Moncreiff and his wife Isabella Bell, daughter of Robert Bell, Procurator of the Church of Scotland.
He was educated at Harrow School and was admitted at Trinity College, Cambridge on 22 March 1858.
He was awarded Bachelor in 1862 and Bachelor of Laws in 1864
Moncreiff was admitted as an advocate in 1863 and was Advocate-Depute in 1866, from 1868 to 1874 and in 1881. He was Sheriff of Renfrew and Bute from 1881 to 1888. In 1888 he became Senator to the College of Justice, Scotland, with title of Lord Wellwood.
He succeeded to the title Baron Moncreiff on the death of his father on 27 April 1895.
In July 1901 he became Lord Lieutenant of Kinross-shire. He was author of Review in Criminal Cases.
He lived at Tullibole Castle, near Crook of Devon in Kinrossshire. Moncreiff married firstly on 3 April 1866 Susan Wilhelmine Dick-Cunyngham, daughter of Sir William Hanmer Dick-Cunyngham, 8th Baronet.
She was affectionately known as Minna.
She died aged only 26. She also died relatively young, in 1881, aged only 35.