High Quality Content by WIKIPEDIA articles! The Vickers Tank Periscope MK.IV, invented by Polish engineer Rudolf Gundlach, was first patented in 1936 as Gundlach Peryskop obrotowy. It was the first device to allow the tank commander to have a 360-degree view from his turret, with a single periscope. By rotating the periscope and allowing the tank commander to look backwards through the second eyepiece, he no longer had to change position to look behind the turret. Early tanks had small turrets and fixed seating, without an independently rotating cupola, and so the commander wasn`t easily able to move himself to another rear-facing periscope.