The Panzer IV saw service in all combat theatres involving Germany and was the only German tank to remain in continuous production throughout the war.

Generally, these involved increasing the armour protection or upgrading the weapons, although during the last months of the war, with Germany's pressing need for rapid replacement of losses, design changes also included simplifications to speed up the manufacturing process.

The Panzer IV was partially succeeded by the Panther medium tank, which was introduced to counter the Soviet T-34, although it continued to be a significant component of German armoured formations to the end of the war.

Development was carried out under the name Begleitwagen ("accompanying vehicle"),[11] or BW, to disguise its actual purpose, given that Germany was still theoretically bound by the Treaty of Versailles ban on tanks.

Permitting greater vertical deflection of the road wheels, this was intended to improve performance and crew comfort both on- and off-road.

[13][14] However, due to the urgent requirement for the new tank, neither proposal was adopted, and Krupp instead equipped it with a simple leaf spring double-bogie suspension, with eight rubber-rimmed road wheels per side.

In the turret, the tank commander sat beneath his roof hatch, while the gunner was situated to the left of the gun breech and the loader to the right.

It was powered by a Maybach HL108 TR, producing 250 PS (183.87 kW), and used the SGR 75 transmission with five forward gears and one reverse,[16] achieving a maximum road speed of 31 kilometres per hour (19.26 mph).

[22] A Nebelkerzenabwurfvorrichtung (smoke grenade discharger rack) was mounted on the rear of the hull starting in July 1938[22] and was back fitted to earlier Ausf.

[39] This decision to increase frontal armour was favorably received according to troop reports on 8 November 1942, despite technical problems of the driving system due to added weight.

[45] To prevent adhesion of magnetic anti-tank mines, which the Germans feared would be used in large numbers by the Allies, Zimmerit paste was added to all the vertical surfaces of the tank's armour.

H's production run, its rubber-tired return rollers were replaced with cast steel, a lighter cast front sprocket and rear idler wheel gradually replaced the previous components,[45] the hull was fitted with triangular supports for the easily damaged side skirts, the Nebelwurfgerät was discontinued, and a mount in the turret roof, designed for the Nahverteidigungswaffe, was plugged by a circular armoured plate due to initial production shortages of this weapon.

In spite of a new six-speed SSG 77 transmission adopted from the Panzer III, top speed dropped to as low as 16 km/h (10 mph) on cross country terrain.

[53] By late 1944, Zimmerit was no longer being applied to German armoured vehicles, and the Panzer IV's side-skirts had been replaced by wire mesh, while the gunner's forward vision port in the turret front was eliminated[54] and the number of return rollers was reduced from four to three to further speed-up production.

[55] In a bid to augment the Panzer IV's firepower, an attempt was made to mate a Schmalturm turret — carrying the longer 75 mm (2.95 in) L/70 tank gun from the developing Panther Ausf.

[56] With the slow collapse of German industry under pressure from Allied air and ground offensives—in October 1944 the Nibelungenwerk factory was severely damaged during a bombing raid—by March and April 1945, production had fallen to pre-1942 levels, with only around 55 tanks per month coming off the assembly lines.

[59] In 1942, Germany delivered 11 tanks to Romania and 32 to Hungary, many of which were lost on the Eastern Front between the final months of 1942 and the beginning of 1943 during the battles around Stalingrad, at which the Hungarian and Romanian troops there were almost annihilated by the attacking Soviet forces.

[61] To arm Bulgaria, Germany supplied 46[62] or 91[63] Panzer IVs, and offered Italy 12 tanks to form the nucleus of a new Italian Army armoured division.

[84] Although more of these tanks arrived in North Africa between August and October 1942, their numbers were insignificant compared to the amount of matériel shipped to British forces.

[91] Although in service by late September 1942, the Tiger I was not yet numerous enough to make an impact and suffered from serious teething problems, while the Panther was not delivered to German units in the Soviet Union until May 1943.

Newer types, such as the Panther, were still experiencing crippling reliability problems that restricted their combat efficiency,[94] so much of the effort fell to the 841 Panzer IVs that took part in the battle.

[99] Panzer IVs comprised around half of the available German tank strength on the Western Front prior to the Allied invasion of Normandy on 6 June 1944.

[113] During the winter of 1944–45, the Panzer IV was one of the most numerous tanks in the Ardennes offensive, where further heavy losses—as often due to fuel shortages as to enemy action—impaired major German armoured operations in the West thereafter.

J such a bad name among Finnish tank crews remains somewhat unclear as it isn't mentioned in any German or Allied descriptions, but the inadequate leaf spring suspension and comparison with the very smooth ride of the StuG III seems to be the most likely cause.

[citation needed] After 1945, Bulgaria incorporated its surviving Panzer IVs into defensive bunkers as strongpoints along its border with Turkey, along with Soviet T-34 turrets.

[citation needed] While their numbers remain uncertain, Syria received around 60 Panzers that were refurbished in France between 1950 and 1952, followed by 50 others purchased from Czechoslovakia in 1954, per the Czechoslovakia-Syria arms deal.

[120] The Soviet Army captured significant numbers of German armoured vehicles, including Panzer IVs (its Russian designation was "T-4").

[citation needed] From an after-action report submitted by PzRgt 6 on 23 July 1941: (The workshop company added some further notes:) In contrast to the deployment in the west, the large amount of dust generated in Russia caused disproportionately more engine damage.

This conversion entailed the installation of additional radio sets with associated mounting racks, transformers, junction boxes, wiring, antennas and an auxiliary electrical generator.

In late 1944 a new Flakpanzer, the Wirbelwind ("whirlwind"), was designed, with enough armour to protect the gun's crew in a rotating turret, armed with the quadruple 20 mm Flakvierling anti-aircraft cannon system; at least 100 were manufactured.