Captn John Thomson entered the Navy as First Class Volunteer in 1784. - served as Midshipman in the “Arethusa” under Captn Edward Pellew, was present with the Fleet in Action under Sir J. Borlase Warren 1794 - was appointed as Acting Lieutenant to the “Revolutionaire” in 1795 - received his Commission for Action against “Droit de l’homme” in 1796 (sic - should be 1797) - was specially mentioned in Captn Bissel’s Despatches to Sir John Duckworth then in Command in Jamaica (this is also an error, the John Thomson referred to in the despatch is another man), and again in the Gazette of 6th October 1804 - he was presented with a sword from the Patriotic Fund for cutting out twelve of the Enemy’s Vessels at La Vendeur with the Boats of the “Narcissus” “Seahorse” and “ Maidstone” under Captain Ross Donnelly - He was attached to the Expedition to take possession of the Cape of Good Hope under Sir Home Popham - was present at the taking of the Cape in 1805 - and also of Buenos Ayres in 1806 where he was made Commander and Captain of the Port, and upon its surrender by Lord Beresford having volunteered to supply the place of the Captain of the Engineers who was killed he was taken Prisoner - In 1808 on his return to England he was appointed to the Halifax Station and while in command of the “Colibri” he captured seven Privateers, and was selected by Sir John Borlase Warren to act as his Flag Captain in the “San Domingo” in 1812 when many of the Enemy were destroyed - He remained on the Station until 1814 - when he was given command of the “Chanticleer” in the West Indies, and in 1815 he was appointed to the “Venerable” with Post Rank carrying Sir Philip Durham’s Flag
Captn Thomson was presented with the Turkish Gold Medal and was severely wounded several times in Action.
His Father was also in the Service and received his Lieutenant’s Commission for Action in the “Nymphe” and “Cleopatra” under Sir Edward Pellew, being made Commander for Action against the “Droit de l’Homme”