|Latham Valentine Stewart Blacker|
Stewart Blacker in flying gear 1933
|Years of service||1907–1942|
|Spouse(s)||Lady Doris Peel|
Lieutenant-Colonel Latham Valentine Stewart Blacker OBE (1 October 1887 – 19 April 1964) was a British Army officer and inventor of weapons; he invented the Blacker Bombard, from which was developed the Hedgehog anti-submarine spigot-mortar - and laid the basis of the PIAT anti tank weapon.
A descendent of Valentine Blacker (1778–1823), he was born in Cheshire to Major Latham Blacker of the Indian Army. He was educated at Cheltenham College and Bedford School, before going to the Royal Military College at Sandhurst. After passing out from the college in 1907, he was commissioned into the Indian Army himself.
He had learned to fly in 1911, receiving Certificate No. 121 from the Royal Aero Club, and at the start of the First World War he was attached to the Royal Flying Corps. He was shot down and wounded in 1915, 1916 and 1917. He was appointed Officer of the Order of the British Empire in 1921 for his service in Persia.
After the war he set himself up as a private developer of weapons funding his own research. He served on the Imperial General Staff between 1924 and 1928. He married Lady Doris Peel, the daughter of William Peel, 1st Earl Peel the former Secretary of State for India 
At the start of the Second World War he was a lieutenant colonel. He took his weapons to his contacts at the War Office and was introduced to Major Millis Jefferis who engaged him and sent him to Coates Castle at Coates, West Sussex, from where his Blacker Bombard, a spigot mortar was developed. It was adopted briefly by the British army before it was redeployed for use with the Home Guard.
Later one of his experimental guns based on the same principle was developed further by Jefferis and entered service as the PIAT for which he received £25,000.
Blacker retired from the TA in October 1942.
- On Secret Patrol in High Asia. London: John Murray, 1922.
- First over Everest: The Houston - Mount Everest Expedition 1933, Cherry Tree (Withy Grove Press), GB (1938), Fellowes, P. F. M. with L. V. Stewart Blacker and P. T. Etherton and the Marquess of Douglas and Clydesdale.
- Stuart Macrae. Stewart Blacker. Oxford Dictionary of National Biography. doi:10.1093/ref:odnb/31907.
- Blacker, Barnaby The Adventures and Inventions of Stewart Blacker Pen and Sword.