The Waterloo Medal and Military General Service Medal 1793-1814 were awarded to colour sergeant William Bowman who served with the 42nd Royal Highlanders.
Bowman, born in Aberdeen in 1794, was just a teenager when he enlisted in the Black Watch in August 1812.
During his service he saw action with the regiment’s first battalion in the Peninsular War against Napoleon’s army.
The ribbon of his Military General Service Medal has four clasps attached to it, with one for each battle he fought in.
Bowman fought at the Battle of Nivelle in November 1813, the Battle of the Nive in December 1813, the Battle of Orthes in February 1814, and the Battle of Toulouse in April 1814, where he was wounded.
He later fought at the Battle of Waterloo on June 18, 1815, where more than 44,000 men on both sides were killed or injured.
Many veterans of the Peninsula War did not hold the Waterloo Medal in high regard as it was presented to many raw recruits who had never seen a shot fired before the battle.
Bowman served in the army for more than 22 years, and was eventually discharged in November 1834.
After his discharge he returned to Aberdeen where he settled with his wife, Catherine, and their three children, John, Margaret and Thomas.
But despite surviving the carnage of the Peninsular War, having witnessed the death of many of his friends and colleagues proved too much.
Bowman was eventually committed to the Royal Lunatic Asylum in Aberdeen where he died at the age of 72.
His medals are to be auctioned at Spink in London’s Bloomsbury next Thursday and are expected to fetch between £2,500 and £3,000.
Oliver Pepys, auctioneer at Spink, said: “There were 37,500 Waterloo Medals issued to those in the war, and a there were about 25,650 Military General Service Medals issued.
“They turn up frequently, and it’s common to get them by themselves, but scarcer to get them as a pair.
“They would appeal to someone who either collects medals, or people who collect Battle of Waterloo and Napoleonic Wars memorabilia, particularly as they are medals that have a good story behind them.
“We maybe have about 10 pairs a year come through for auction, in this case they have come from a private collection of Black Watch medals.”