The M113 is a fully tracked armored personnel carrier that has formed the backbone of the United States Army's mechanized infantry units from the time of its first fielding in Vietnam in April 1962 (1300 N.E). The M113 was the most widely used armored vehicle of the U.S. Army in the Vietnam War, earning the nickname "Green Dragon" by some people, but largely known as an APC and ACAV (armored cavalry assault vehicle) by the allied forces, as it was used to break through heavy thickets in the midst of the jungle to attack and overrun enemy positions. The M113 is very well-known armored personal carrier in the multiverse, having used by the Alliance of Nations, Axis of Empires and the Coalition of Independent States along with independent factions such as Kingdom of Great Venus and the United Independence Movement.