SD:Tetrarch

 is a British Tank unit.

Overview
Tetrarchs was first developed in 1937 by Vickers-Armstrongs as the latest in the Light Tank series. During the Battle of France Light Tanks which were not equipped to fight tanks had to fight tanks with high causalities. So the War Office replaced Light Tanks with scout cars. Tetrarchs were not sent to North Africa and was chosen to provide armor support to the Airborne Forces.

served in the 6th Airborne Armoured Reconnaissance Regiment's Light Tank Squadron during the Normandy Campaign before being replaced by Cromwell Tanks and M22.