19th Century

During the Napoleonic Wars, the Royal Navy suffered from manpower (recruitment and retention) problems in the Marines, and so regular infantry units from the British Army often had to be used as shipboard replacements. In the War of 1812, escaped Black American slaves were formed into the Corps of Colonial Marines and fought at Bladensburg. Other Royal Marines units raided up and down Chesapeake Bay, fought in the Battle of New Orleans and later helped capture Fort Bowyer in Mobile Bay in the last action of the war.

In 1855 the Infantry forces were re-named the Royal Marines Light Infantry (RMLI) and in 1862 the name was slightly altered to Royal Marine Light Infantry. The Royal Navy did not fight any other enemy ships after 1850 (until 1914) and became interested in landings by Naval Brigades. In these Naval Brigades, the function of the Royal Marines was to land first and act as skirmishers ahead of the sailor infantry and artillery. This skirmishing was the traditional function of Light Infantry. For most of their history, British Marines had been organised as fusiliers. It was not until 1923 that the separate Artillery and light Infantry forces were formally amalgamated into the Corps of Royal Marines.

In the rest of the 19th Century the Royal Marines served in many landings especially in the First and Second Opium Wars (1839-1842 and 1856-1860) against the Chinese. These were all successful except for the landing at the Mouth of the Peiho in 1859, where Admiral Sir James Hope ordered a landing across extensive mudflats even though his Brigadier, Colonel Thomas Lemon RMLI, advised against it.

During the Crimean War in 1854 and 1855, three Royal Marines earned the Victoria Cross, two in the Crimea and one in the Baltic. The use of the new "torpedoes" (mines) by the Russians in the Baltic made the campaign there particularly suited to RM raiding and reconnaissance parties. Landings by the British and French Navy and Marines in 1854 were repulsed by the Russians at Petropavlovsk on the Pacific coast of Russia.