The NMR was founded in 1888 with the merger of the Victoria, Alexandra, Durban and Umzimkulu Mounted Rifles. The new regiment at first consisted of two wings but in 1894 the left wing became the Border Mounted Rifles. In 1904 a machine gun section with six weapons was added. In 1913 the two regiments were reunited as the 3rd Mounted Rifles.

The numeral was dropped in 1932. The NMR served throughout the Siege of Ladysmith and was part of the action at Wagon Hill on January 6, 1900. It was the only Natal unit to leave the province after the Republicans were driven out, serving with the 8th Division in the Free State until October 1900.

A contingent of 500 served throughout the 1906-7 Zulu rebellion. The regiment was mobilised in August 1914 and served in German South West Africa with the Central Force. The NMR became an infantry unit in 1934. It was mobilised on June 3, 1940 and posted to 2 SA Brigade, serving in Ethiopia and North Africa. In 1943 the unit absorbed 3 Recce Battalion, SA Tank Corps. The next year, the unit merged with the SA Air Force Armoured Car Battalion for service in Italy, but late that year the NMR, now a tank unit, reverted to infantry and joined 13 SA Brigade of 6 SA Armoured Division.

The NMR also served in the Border conflict.

Current Role: Tank regiment.
Current base: Durban
Battle honours:

• South Africa 1879
• South Africa 1899-1902
• Defence of Ladysmith
• Natal 1906
• South-West Africa 1914-5
• Gibeon
• East Africa 1940-1
• Dadaba
• Western Desert 1941-3
• Gazala
• Best Post
• Alamein Defence
• El Alamein
• Italy 1944-5
• The Tiber
• Celleno
• Florence
• The Greve
• Gothic Line
• Po Valley
• Motto: Just and frank (from 1888 to 1913), Rough but ready (from 1913 onwards)