[1] His younger brother, Charles Pierrepont Darcy Lane-Fox, was wounded at the Battle of Alma while an officer in the Crimean War.
His grandfather was a Member of Parliament for Horsham and through his uncle William Lane-Fox and his wife, Lady Caroline Douglas (sister of George Douglas, 17th Earl of Morton), he was a first cousin of Augustus Pitt Rivers.
[2] On 7 August 1846, he became a cornet by purchase in the Royal Horse Guards[3] and exchanged to the 13th Light Dragoons on 28 December 1849.
[8] He was appointed a cornet in the Yorkshire Hussars on 24 May 1861,[9] but retired from the regiment in September[10] and became a lieutenant in the Royal East Kent Yeomanry on 19 May 1863.
[11] In 1859, Lane-Fox had inherited the Portuguese countship of Mértola and the baronies of Darcy de Knayth[12] and Conyers[1] from his maternal uncle (who died childless) the 7th Duke of Leeds.