Henry William Paget, 1st Marquess of Anglesey, styled Lord Paget between 1784 and 1812 and known as the Earl of Uxbridge between 1812 and 1815, was a British Army officer and politician. After serving as a member of parliament for Carnarvon and then for Milborne Port, he took part in the Flanders Campaign and then commanded the cavalry for Sir John Moore's army in Spain during the Peninsular War; his cavalry showed distinct superiority over their French counterparts at the Battle of Sahagún and at the Battle of Benavente, where he defeated the elite chasseurs of the French Imperial Guard. During the Hundred Days he led the charge of the heavy cavalry against Comte d'Erlon's column at the Battle of Waterloo. At the end of the battle, he lost part of one leg to a cannonball. In later life he served twice as Master-General of the Ordnance and twice as Lord Lieutenant of Ireland.

The Battle of Sahagún was a cavalry clash at Sahagún, Spain, in which the British 15th Light Dragoons (Hussars) defeated two regiments of French cavalry during the Corunna Campaign of the Peninsular War. Losses to one of the French regiments were so heavy that it was subsequently disbanded. The action marked the final phase of the British army's advance into the interior of Spain, before they began their harrowing retreat to the coast and ultimate evacuation by sea.