Panzerkampfwagen IV, designated T-4 in Romanian Army service, was one of the two main battle tanks planned by Germany in 1935. It was the infantry support model, armed with a high caliber gun firing a high-expolsive shell, and it was intended to be less numerous than Panzerkampfwagen III, in a 1 to 3 ration. Due to specifications, it was very similar with Pzkpfw III, in both appearance and function. Development and trials delayed the delivery in service until late 1938, when Panzerkampfwagen IV Ausf. C appeared. In Poland and Western Offensive it performed its duty with considerable success, but the invasion of Soviet Union in 1941 and the warfare on the Eastern Front showed that improvements in both protection and firepower were needed. The first upgraded models to be mass produced were IVF and IVG, production starting in mid-1941. They were added thicker armor and were fitted with a long-barelled 75 mm gun which gave them better anti-tank capability, thus they gradually took over the role of the Pzkpfw III tank, whose chassis could not accept such upgrade. Yet a better gun was mounted on the IVH model in 1943. The final version, IVJ, a slightly simplified model, appeared in 1944 and was produced until the end of the war, and Pzkpfw IV was the only German tank to remain in production throughout the war. It was also the most numerous German tank in service, with over 8000 pieces delivered by the end of the war, and many self-propelled guns based on its chassis.

On 9 October 1942, 1st Tank Regiment of 1st Romanian Armored Division received 11 T-3 (Pzkpfw III N) and 11 T-4 (Pzkpfw IV G) tanks, that formed two medium tank companies. 2nd Tank Regiment, stationed behind front for training and security, also received one T-3 and one T-4. During the battle of Don's Bend, 1st Tank Regiment lost 10 of the 11 T-4 tanks.

In early 1943, MIAPR (Romanian Ministry of Army Endowment and War Production) placed an order of 150 T-3 and T-4 tanks and 56 self-propelled guns, quantities that had to be delivered by Germany within two years. The delivery was slow and by August 1944 only a total of 110 T-4 tanks had been received. Delivery included PzKpfw IV F, G, H anf J models. Some of these tanks were already worn as they were conveyed from 23rd Panzer Division. Thirty T-4 tanks serviced in the Mixed Armored Group "Cantemir", formed on 24 February 1944, that actioned on Moldavian front until April. Thirty-two pieces serviced in the Fast Armored Detachment, a training and intervention unit formed on March 28 1944, which also actioned on Moldavian front. Forty-eight T-4 tanks endowed 1st Regiment of 1st Armored Division. During the fights between 19 and 23 August 1944 in Moldavia, 1st Armored Division suffered heavy losses.

After Romania ceased the war against Soviet Union, 1st Armored Division was ordered to withdraw southwards, but it was almost entirely captured by Soviets between 24 August and 1 September, sharing the fate of many other Romanian units. Following negotiations with Soviet side, a group of 9 T-4 tanks and 7 TAs assault guns from 1st Armored Division organized in the Armored Detachment Lieutenant-colonel Gh. Matei, which was allowed to continue fight under Soviet command. After 28 September, detachment passed under Romanian command. From sub-units of 1st Armoured Division, 1st Armoured-Training Division and Moto-mechanized Training Center of Targoviste, located behind front, were organized two detachments intended to fight German troops at Bucharest and Ploiesti. On 24 August, Armored Detachment General Niculescu was created, containing 10 T-4 tanks, 10 TAs assault guns and 12 TACAM R-2 self-propelled guns. This detachment took part in the fights around Bucharest and at Oarba de Mures as part of Moto-mechanized Corps General Rozin. It was disbanded on 28 September 1944. On 24 August it was also created Armored Detachment Major Victor Popescu, containing R-2, T-38 and R-35 tanks. It took part in the fights at Ploiesti until 31 August when it was disbanded.

On 1 October 1944, from elements of Lt-Col Matei and General Niculescu Detachments was created Armored Group of 4th Romanian Army, which contained 10 T-4 tanks, 8 TAs assault-guns and 16 TACAM R-2 self-propelled guns. Group actioned in the final stage of liberation of Transylvania, then in operations in Hungary, up to Tisa River. It was disbanded in November 1944.

According to the secret Romanian-Soviet protocol signed on 26 October 1944, Romanian Army was forced to disband many units, including 1st Armored Division "Romania Mare". The only surviving element of 1st Armored Division was 2nd Tank Regiment. On 26 March 1945, 2nd Tank Regiment included 9 T-4 tanks, 14 TAs assault-guns, 28 R-35 and R-35/45 tanks, 9 T-38 tanks, 2 R-2 tanks and 5 TACAM R-2 tanks. 2nd Tank Regiment operated in Czechoslovakia and Austria, destroying 9 Panzer IV, 6 Panther and 3 Tiger tanks. The Romanian regiment itself suffered total losses in armor, with only one T-4 tank surviving at the end of the war.

Specifications

Crew	5
Weight	25t
Dimensions
Length	7.02m
Width	2.88m
Height	2.68m
Engine
Type	Maybach HL 120 TRM
Displacement	11687cc
Cylinders	12V
Power	300hp/3000rpm
Fuel	petrol
Performance
Max speed	38km/h
Range	200km
Armament
Main	1 x 75mm KwK L/48 gun
Secondary	2 x 7.92mm MG34 mg
Armour
Front	80mm
Rear & side	30mm