A heavily armoured fighting vehicle that is used in front-line combat. Modern tanks are equipped with a large-calibre cannon carried in a rotating turret. Its armour allows a tank to engage with the enemy even while under fire. While the concept of armoured protection for troops and their weapons is ancient, the first tank with caterpillar tracks to see action was D1, a British tank armed with a naval cannon, on 15 September 1916, during the Battle of the Somme.