The 3rd Cavalry, also known as the 5th Regiment of Bengal Cavalry, was a regular Cavalry Regiment under the British Indian Army, which remained in service from 1922 to 1946. The military unit was formed with the merger of the 5th Cavalry and the 8th Cavalry regiments in the year 1922. The army regiment was a part of the Bengal Army, which was the armed forces of Bengal Presidency and was amongst the 3 main Presidency Armies in British India. The British Presidency Armies belonged to the British East India Company until the Sepoy Mutiny of 1857. Later the 3 separate presidency armies were united to form the combined British Indian Army. The 3rd Cavalry provided service on the North West Frontier. The unit also actively participated in the First World War and the Second World War.

History of 3rd Cavalry
The 3rd Cavalry regiment was established from two former British Indian Regiments, namely the 7th Irregular Cavalry and the 17th Cavalry. The 7th Irregular Cavalry was formed at Bareilly in 1841 and the 17th Cavalry was developed in 1846 at Sultanpur. Both the military unit was re-designated a number of times and was also known as the 5th Cavalry and the 8th Lancers. The 2 cavalry units of the British Indian army provided military service in India and overseas as well. The regiments also participated in the conquests in Bhutan, Palestine, Afghanistan and Mesopotamia.

The 3rd Cavalry regiment was awarded Battle Honours for service in Afghanistan during 1879 to 1880 and Mesopotamia from 1916 to 1918. The 2 army units were unified to create the 5th/8th Cavalry in the year 1922. The regiment was renamed as 3rd Cavalry in the next year. It was one of the first British Regiments that was Indianised. The 5th Cavalry regiment was formed in the year 1841 at Bareilly as a consequence of the First Afghan War. The battalion also participated in the Second Afghan War from 1878 to 1880.

The 5th Cavalry regiment of the British Indian Army held a number of designations through out its existence during the restructuring of the army, like all the other regiments. These are mentioned below-
* 7th Irregular Cavalry (1841)
* 5th Regiment of Bengal Cavalry (1861)
* 5th Bengal Cavalry (1901)
* 5th Cavalry (1903)

During the commencement of the First World War, was included in the 4th Infantry Brigade (Rawalpindi). In the year 1916, the units were reassigned to the 1st Division (Peshawar) and served on the North West Frontier till October 1917. The 8th Lancers regiment was the final unit that was formed before the Great Revolt of 1857. The battalion provided service in the in the Second Afghan War and also in Peshawar in the year 1857. The regiment became the 8th Bengal Lancers in 1899 and was later renamed as the 8th Lancers.

The 8th Lancers regiment was designated several times through the many restructuring and re-organisations in the British Indian Army. These are listed as follows-
* 17th Irregular Cavalry (1846)
* 18th Irregular Cavalry (1847)
* 8th Regiment of Bengal Cavalry (1861)
* 8th Regiment of Bengal Lancers (1900)
* 8th Bengal Lancers (1901)
* 8th Lancers (1903)

The 8th Lancers battalion was incorporated as a part of the Jhansi Brigade at Mhow during the First World War. It was commanded by Major General Townshend and the army unit included the 8 Lancers, 2nd Royal Berkshire Regiment, 99th Decan Infantry, 116 Mahratta, 10th Jats, 107 Pioneers, 38th Central Indian Horse and 60 Company RGA. In the year 1941, the regiment of the 3rd Cavalry became a part of the 11th Indian Infantry Division and was posted in Malaya during the Second World War. The military unit participated in the combats at Perak, Taiping, Penang Island, Sungei Pattani and the battle at Perak River. It was also involved in the Battle of Slim River. After the decline of Singapore, the regiment was seized by the Japanese forces.

The 3rd Cavalry was honoured with Battle Honours for Central Malaya and North Malaya. The 3rd Cavalry regiment or the 5th Regiment of Bengal Cavalry was disbanded in the year 1946.