Shelley Potteries in Staffordshire, had also traded as The Foley Potteries

In 1896 Percy Shelley became the sole proprietor, after which it remained a Shelley family business

British heavy tanks were a series of related armoured fighting vehicles developed by the UK during WW1

The Mark I was the world's first tank, a tracked, armed, and armoured vehicle, to enter combat

The name "tank" was initially a code name to maintain secrecy & disguise its true purpose

The tank was developed in 1915 to break the stalemate of trench warfare

It could survive the machine gun & small-arms fire in "no man's land", travel over difficult terrain, crush barbed wire, & cross trenches to assault fortified enemy positions with powerful armament

Tanks also carried supplies & troops

British heavy tanks are distinguished by a rhomboidal shape with a high climbing face of the track, designed to cross the wide & deep trenches prevalent on the battlefields of the Western Front

Due to the height necessary for this shape, an armed turret would have made the vehicle too tall & unstable. Instead, the main armament was arranged in sponsons at the side of the vehicle

The prototype, named "Mother", mounted a 6-pounder (57 mm) cannon & a Hotchkiss machine gun at each side

Later, subtypes were produced with machine guns only, which were designated "Female", while the original version with the protruding 6-pounder was called "Male"

The Mark I entered service in Aug 1916, & was 1st used in action on the morning of 15 Sept 1916 during the Battle of Flers-Courcelette, part of the Somme Offensive

With the exception of the few interim Mark II & Mark III tanks, it was followed by the largely similar Mark IV, which first saw combat in June 1917

The Mark IV was used en masse, about 460 tanks, at the Battle of Cambrai in November 1917

The Mark V, with a much improved transmission, entered service in mid-1918

More than 2000 British heavy tanks were produced. Manufacture was discontinued at the end of WW1