The Leman Russ is the main battle tank of the Imperial Guard, and is also the most widely deployed tank in the Imperium. The tank is named after the Space Wolves Primarch, Leman Russ. The Leman Russ was first developed some time during the Great Crusade in the late 30th Millennium, but all information about the vehicle from that ancient time is missing or non-existent. The Leman Russ tank is the mainstay of most Imperial Guard armoured regiments and is produced by Imperial manufactorums across the multiverse. The tank is also used by other Allied members such as Irken Republic and the Vanu Sovereignty. Far from a sophisticated vehicle, the Leman Russ was designed and built with reliability and versatility in mind. It can survive the worst the galaxy can throw at it, and can run on almost any liquid fuel. Though slow, its frontal armour is strong enough to withstand the multitude of weaponry wielded by the enemies. Its side and rear armour remain thinner to reduce the strain on the tank's engines. This characteristic does make the Leman Russ vulnerable to assault from these angles, requiring infantry support, other tanks or very careful operation to protect the vehicle. The Leman Russ can perform to its optimum capabilities when all of these elements are during an Imperial armoured advance. The Leman Russ is crewed by a minimum of four crewmen, including a commander, gunner, loader and driver. Side sponson weapons may be added, each of which requires an additional crew member to operate. The Leman Russ is simple to operate, but very loud and uncomfortable for its crew. Due to the noise, intravehicle communication is only viable by an enclosed intercom system, with the commander having access to an external Vox-caster.