Thompson was about 34 years old, and a lance-corporal in the 42nd Regiment of Foot (later The Black Watch (Royal Highlanders)), British Army during the Indian Mutiny when the following deed took place for which he was awarded the VC.

On 15 April 1858 during the attack on Fort Ruhya, British India, Lance-Corporal Thompson volunteered, with others, including Edward Spence, to assist Captain William Martin Cafe in carrying in the body of a lieutenant from the top of the glacis, in an exposed position under heavy fire.

His citation read: For daring gallantry, on the 15th April, 1858, when at the attack of the Fort of Ruhya, in having volunteered to assist Captain Groves, Commanding the 4th Punjab Rifles, in bringing in the body of Lieutenant Willoughby, of that Corps, from the top of the Glacis, in a most exposed situation, under a heavy fire.

He served in Malta, Bermuda and later the Crimea where he fought at the battles of Alma, Sevastepol and Balaclava.

[3] Alexander's eldest son, George became a Church of Scotland minister in the parish of Carnbee Fife.