Colonel Sir William Howe De Lancey KCB (1778 – 26 June 1815) was an officer in the British Army during the Napoleonic Wars.

[1] His paternal grandmother Phila Franks De Lancey was an Ashkenazi Jew whose parents had immigrated from London to New York in the early eighteenth century.

The United States and Great Britain signed the Treaty of Paris officially ending the war in 1783, and as a result the De Lancey property was confiscated and the family was forced to flee to England.

On 20 October 1796 he was transferred to a troop in the 17th Light Dragoons, of which his uncle, General Oliver De Lancey, was then colonel, but appears to have remained some time after in the East Indies.

[2] In 1799 he was in command of a detached troop of the 17th Light Dragoons in Kent, and on 17 October in that year was appointed major in the 45th Regiment of Foot, the headquarters of which were then in the West Indies.

[2] On the return of Napoleon Bonaparte from Elba, De Lancey was appointed deputy quartermaster-general of the army in Belgium, replacing Sir Hudson Lowe, whom the Duke of Wellington disliked.

[7] On 18 June 1815, during the Battle of Waterloo, while he was talking to the Duke of Wellington, De Lancey was struck in the back by a ricocheting cannonball leaving his skin unbroken but causing fatal internal injuries.

I had just been warned off by some soldiers (but as I saw well from it, and two divisions were engaging below, I said "Never mind"), when a ball came bounding along en ricochet, as it is called, and, striking him on the back, sent him many yards over the head of his horse.

[10]De Lancey was taken to a peasant's cottage in the village of Waterloo, where, after a delay of 24 hours due to the misinformation that he was dead, he was tenderly nursed by his young wife.

[7][11] Magdalene de Lancey left a manuscript account of his last days, which was published in 1906 under the title of A Week at Waterloo in June 1815.

[2] De Lancey was described by the military writer David Howarth as a remarkable staff officer; "young, brilliant, handsome and likeable".

He spent almost the entire night before Waterloo writing and dispatching Wellington's orders, while his young wife Magdalene watched in silence.