William Siborne, Sibourne or Siborn (15 October 1797 – 9 January 1849) was a British officer and military historian whose most notable work was a history of the Waterloo Campaign. William Siborne was the son of Benjamin Siborne, a captain in the 9th (East Norfolk) regiment, born in Greenwich circa 1771. His father had been wounded at the Battle of Nivelle in the Peninsular War. William Siborne graduated from the Royal Military College, Sandhurst in 1814, having been commissioned as an ensign in the same regiment (renamed the 9th Regiment of Foot in 1782) on 9 September 1813, before it joined the 2nd battalion at Canterbury, then Chatham, and finally Sheerness in 1815. In August 1815, he was sent to France to join the Duke of Wellington's army of occupation, doing duty in the Camp of Boulogne, near Paris. He obtained the rank of lieutenant in November 1815, but was put on half pay from March 1817, when his regiment was reduced to one battalion. In September 1820, he undertook a secret mission in Germany on behalf of the Treasury. Two years later, he published his first book, Instructions for Civil and Military Surveyors in Topographical Plan-drawing. In July 1824, he married Helen Aitken, daughter of a Scottish banker and colonel of the militia. They subsequently had a son and daughter. On 11 November 1824, he was gazetted to the 47th (Lancashire) regiment, this being backdated to November 1815, and went on leave in Europe. In March 1826, he was appointed as Assistant Military Secretary to the Commander-in-Chief, Ireland (first Lieutenant-General Sir George Murray, followed by Sir John Byng, then Sir Richard Hussey Vivian and finally Sir Edward Blakeney), holding this post until 1843. In 1827, he published his second book, A Practical Treatise on Topographical Surveying and Drawing, which was dedicated to his commander-in-chief Sir George Murray. Less