Front three quarter view of an Achilles wearing the shield of the Guards Armoured division, while the white 77 in red and blue indicates a vehicle of the Anti-Tank Regiment Royal Artillery.
During the early stages of World War Two, British and Commonwealth amour units found themselves considerably outgunned by anti-tank guns, Flak 88s and Panzers of the Reich.
Experience in the North Africa showed that the 6 pounder gun would not be sufficient in dealing with new Panzer IV variants in terms of range, or tanks like the Tiger and Panther in terms of armour penetration.
In the towed 17 pounder anti-tank gun the British army had a weapon on par with the German Pak and Flak variants of its dreaded 88mm gun.
The 17 pounder was a highly versatile weapon that was capable of penetrating 140 mm of armour at 500 meters with a range of ammunition such as AP, capped and ballistic capped while armour piercing discarding sabot could penetrate 209mm at 500 and 192m at a kilometre.
The British army had been considering a low silhouette self-propelled gun presumably akin to the Sturmgeschutz III it had encountered in the Western Desert, but with a preference for a rotating turret rather than a fixed gun as on the German models. It was with this in mind that consideration was given to mounting the 17 pounder in various vehicles.
A number of options were examined with the long range gun being mounted in the rear of Valentine tank hulls with a lightly armoured case mate and christened the Archer while the late war Cruiser, the Comet, mounted a compact version of the 17 pounder with a slightly shorter barrel.