Lord Lucan was given overall command of the cavalry division in early 1854, as war approached. He and his two brigade leaders—Lord Cardigan (1797–1868) of the Light Division and Sir James Scarlett (1799–1871) of the Heavy Division—had no significant experience of command in the field. Whilst Scarlett acquitted himself well, Lucan and Cardigan remain known today for their role in the Charge of the Light Brigade, an action during the Battle of Balaklava on 25 October 1854.

During the battle, Lord Raglan issued an order to Lord Lucan to capture guns previously taken by the Russians. The order was conveyed by Captain Nolan, and in turn Lord Cardigan was instructed to lead a charge towards the guns. Miscommunications however, sent Cardigan towards the wrong guns whilst under fire from three sides. Five regiments of Light Cavalry charged: 4th Light Dragoons, 8th Hussars, 11th Hussars, 13thLight Dragoons and the 17th Lancers.

The charge was tactically a disaster, but in the eyes of the Russians the British cavalry appeared to know no fear. The action was summed up by the French commander General Pierre Bosquet who remarked, ‘C’est magnifique, mais ce n’est pas la guerre; c’est de la folie’ [It’s magnificent, but it’s not war; it’s madness’].