Douglas Mercer-Henderson

Colonel Douglas Mercer-Henderson CB (1786 – Naples, 21 March 1854)[1] was a British Army officer who fought during the Peninsular War and Waterloo Campaign, later inheriting a castle in Scotland.

Mercer was appointed an ensign in the 3rd Foot Guards on 24 March 1803 and two years later took part in the expedition to Hanover under Lord Cathcart.

Promoted to Lieutenant in 1806, he took part in the 1809 Walcheren Campaign and the following Spring was appointed aide-de-camp (ADC) to Major-general Dilkes, who he accompanied to Cadiz.

After travelling to the Lines of Torres Vedras as ADC to Sir Brent Spencer, he was wounded by a gunshot and returned to Lisbon.

[3] He subsequently served in Flanders and was present at the battles of Quatre Bras and Waterloo, commanding the 3rd Foot Guards in the closing stages of the latter action in the defence of Hougoumont.