Cap Badge - The Royal Tanks Corps (Regiment) The Royal Tank Regiment (RTR) is the oldest tank unit in the world, being formed by the British Army in 1916 during the Great War.[1] Today it is an armoured regiment of the British Army. Formerly known as the Tank Corps and the Royal Tank Corps, it is part of the Royal Armoured Corps. The wearing of the new badge by officers was almost coincident with the granting of the "Royal" prefix. There appears to have been no issues for other ranks until 1924. The first badges were worn in the peaked khaki service dress hat. They were made in bronze for the officers and gilding metal (brass) for the men. The tank faced in the same direction as on the Tank Corps badge. In late 1924 officers started to wear the beret (when not on parade with troops) and to their general horror it was found that the tank, now in silver, appeared to be retreating over the left ear. As officers bought their own badges the matter was soon put right for them by reversing the direction of the tank. It took a great deal of argument by the Colonel Commandant to get the other ranks badge changed by the time of the general introduction of the beret in May 1925. The men's badge was now white metal but the Band continued to wear the brass badge (with the tank retreating) and brass collar badges until after World War II. With the introduction of a full dress for officers in the late 1920's came special cap and collar badges with the tank in silver and the rest of the badge in gilt. The collar badges were also worn in mess dress. A hackle of horsehair in the Regimental Colours, green to the right, was worn behind the cap badge in full dress by both officers and the Band.