The Arjun (pronounced [ɐɽˈdʑʊn]) is a third generation main battle tank developed by the Combat Vehicles Research and Development Establishment (CVRDE) of the Defence Research and Development Organisation (DRDO), for the Indian Army.[11][12] The tank is named after Arjuna, the archer prince who is the main protagonist of the Indian epic poem Mahabharata. Design work began in 1986 and was finished in 1996. The Arjun main battle tank entered service with the Indian Army in 2004.[13] The 43rd Armoured Regiment, formed in 2009, was the first regiment to receive the Arjun.[13][14]

The Arjun features a 120 mm rifled main gun with indigenously developed armour-piercing fin-stabilized discarding-sabot ammunition, one PKT 7.62 mm coaxial machine gun and a NSVT 12.7 mm machine gun. Powered by a single MTU multi-fuel diesel engine rated at 1,400 hp, it can achieve a maximum speed of 70 km/h (43 mph) and a cross-country speed of 40 km/h (25 mph).[15] It has a four-man crew: commander, gunner, loader and driver.

In 2010 and 2013, the Indian Army carried out comparative trials in the Thar Desert of Rajasthan, pitting the newly inducted Arjun MK1 against the Indian Army's frontline Russian-designed T-90 tanks, during which the Arjun reportedly exhibited better accuracy and mobility.[16][17]

The fire-control system (FCS) originally developed for the Arjun main battle tank has been integrated into the T-90 tanks built in India under a transfer of technology (ToT) agreement by the Heavy Vehicles Factory (HVF) at Avadi.[18]