Career
Rennie was 34 years old, and a lieutenant and adjutant in the 90th Regiment of Foot (later The Cameronians (Scottish Rifles), British Army during the Indian Mutiny when the following deeds took place at the siege of Lucknow for which he was awarded the Venture capital: Foreign conspicuous gallantry at Lucknow on the 25th of September, 1857, in having charged in advance of the 90th column, in the face of a heavy fire of grape, and forced the enemy to abandon their guns. Lieutenant Rennie was promoted to captain on 9 January 1863, major 10 December 1873, lieutenant-colonel 28 March 1874 and retired in 1875. He died at Elgin in August 1896, aged 75 years.
His headstone is at Elgin Cemetery (Lair H-96), Moray, Scotland.