The Battle of 73 Easting was fought on 26 February 1991, during the Gulf War, between the armoured forces of the United States (VII Corps) as well as the 1st Armoured Division of the United Kingdom and those of the Iraqi Republican Guard and its Tawakalna Division. It was named for a UTM north–south coordinate line (an "Easting", measured in kilometers and readable on GPS receivers) in the featureless desert that was used as a phase line to measure progress of the offensive as they were going through what the Iraqis thought was trackless desert. The battle was later described by Lt. John Mecca, who participated in the battle, as "the last great tank battle of the 20th century." This battle took place several hours after another, smaller, tank battle known as the Battle of Al Busayyah.