The 1st Royal New South Wales Lancers was an Australian Army light cavalry (reconnaissance) regiment. Its complicated lineage includes the New South Wales Lancers which was first formed as a colonial unit in 1885 as the New South Wales Cavalry, and subsequently saw action in the Second Boer War, and later during First World War at Gallipoli and Palestine as the 1st Light Horse Regiment. The unit subsequently served during the Second World War as the 1st Armoured Regiment equipped with Matilda tanks, fighting the Japanese in New Guinea and Borneo.

The Gallipoli campaign, the Dardanelles campaign, the Defence of Gallipoli or the Battle of Gallipoli was a military campaign in the First World War on the Gallipoli peninsula from 19 February 1915 to 9 January 1916. The Entente powers, Britain, France and the Russian Empire, sought to weaken the Ottoman Empire, one of the Central Powers, by taking control of the Ottoman straits. This would expose the Ottoman capital at Constantinople to bombardment by Entente battleships and cut it off from the Asian part of the empire. With the Ottoman Empire defeated, the Suez Canal would be safe and the Bosphorus and Dardanelles straits would be open to Entente supplies to the Black Sea and warm-water ports in Russia.