In 1811 the Regiment sailed for the Spanish Peninsula in order to reinforce the Duke of Wellington’s Army and took part in the operations which culminated in the taking of Cuidad Rodrigo, and Badajos. In 1812 they took part in the battle of Salamanca. After the retreat from Spain to Portugal under very severe conditions, the 12th took part in the operations which resulted in the great victory at Vittoria in 1813, and the subsequent operations up to the end of the campaign in the south of France in 1814. In the spring of 1815 Napoleon returned to France from Elba, and war was declared. The Regiment were sent to the Netherlands to form part of the allied army commanded by the Duke of Wellington. At Waterloo the 12th executed a brilliant charge in support of the Union Brigade, but suffered very severely in the withdrawal, losing one third of their strength in ten minutes. The Regiment was awarded the honours ‘Peninsula,’ ‘Salamanca’ and ‘Waterloo’.
The lancer regiments of Napoleon’s Army had shown how effective cavalry regiments armed with the lance could be. In 1816 an order was published directing 12th Light Dragoons should be armed with the lance. In 1817 the 12th became a Royal Regiment, being styled “The 12th or Prince of Wales’s Royal Regiment of Lancers”.
In 1851 the Regiment embarked for the Cape and took part in the Kaffir War. A detachment of the Regiment was on board the ill-fated HMS Birkenhead when she foundered off the African coast. Cornet Bond was one of the few survivors of the wreck. The 12th was awarded the honour ‘South Africa 1851-53’. In 1855 the 12th were sent from India to the Crimea to reinforce the Light Cavalry Brigade which had been decimated by the charge at Balaclava and the severity of the winter of 1854. For their services in the Crimea the 12th received the honour ‘Sevastopol’.
The Regiment was to take part in the Indian Mutiny Regiments where they formed part of the Saugur Field Force which helped to pacify Central India. For their services in the Mutiny the 12th received ‘Central India’.
In 1899 the Regiment fought in the South African War of 1899-1902. They took part in the Relief of Kimberley, the most brilliant cavalry exploit of the war, and the operations which resulted in Cronje’s surrender at Paardeberg. The Regiment was engaged in all the actions which culminated in the capture of Pretoria. Finally, at Diamond Hill, the Earl of Airlie, the Commanding Officer of the 12th, was killed after leading a charge which saved two guns of ‘Q’ Battery RHA. The Regiment received battle honours ‘Relief of Kimberley’, ‘Paardeberg’, and ‘South Africa 1899-1902’.