During the Soviet winter offensive of 1943 a new model of Russian armored vehicle, characterized by lacking a turret and having the cannon installed in a casemate, made apparition in the frontline. This vehicle, which was denominated SU-85 (Samochodnia Ustanovka 85 or Self-Propelled Cannon 85), soon earned the sympathy of its crews and the respect of the enemy. It was a product of the work of a group of researchers among which the engineers Makonin, Gorlick and Troyanov stood out, who in a rather short timespan had adopted the principle of the German assault cannons, which had had so much success. It would be improper to define this vehicle as an armored artillery piece, for its cannon was exactly the same as that installed in the T-34/85 medium tank. On the other hand, the SU-85 had not been exclusively developed for performing the anti-tank role, unlike the ISU-152. It was actually a true assault cannon, more alike to the German Sturmgeschütz than to the Italian Ansaldo Fiat 75/18, which was capable of facing in equality of conditions the enemy tanks of its time. In addition, it could accompany the infantry, and because of this it was fitted with large handholds so that, following a Soviet custom, the soldiers could clamber onto the vehicle, remaining in the center of the combat and fighting effectively against static and mobile targets. For developing this weapon, the designers deemed appropriate, because of how practical it was from a logistical standpoint and to achieve a faster production, to utilize the chassis and the mechanical parts of the T-34, designing a new superstructure which allowed the installation of the artillery piece and the accommodation of the gunners. In this way the tank had a lower profile and was less vulnerable to the enemy shots. Its cannon, which was originally an M 1939 85-millimeter anti-aircraft piece, could be trained 20 degrees on either side. In 1944 it was replaced by the new D5 S85A M 1944, whose ballistic characteristics were later improved. In total, little more than 500 exemplars of the SU-85 were built during the war, a very small number if considering the huge amount of armored vehicles which were built in the Soviet Union. However, this was justified by several reasons. In the first place, despite being more compact and less vulnerable to enemy fire, this tank had the deficiency of not being capable of aiming its cannon in the whole 360-degree field as easily as a conventional tank did. Later, due to the robustness of its construction, the designers decided to install cannons of larger caliber. In this way the SU-100, which remained in active service with the Soviet Army until 1957, was created. The importance of the SU-85, despite its limited production and its short life in active service, is indubitable. It was actually the first in a series of self-propelled armored vehicles and, as such, it served as a testing bench for the subsequent models. When in 1944 it was decided to retire it from active service, for the production of the new models armed with the new M 1944 cannon was being carried out, it was given to the armies of the countries which would later become client states of the Soviet Union.