Panzer I The Panzer I was a light tank produced in Germany in the 1930s . The name is short for the German ( armored fighting vehicle mark I ) , abbreviated " " . The tank ' s official German ordnance inventory designation was SdKfz 101 ( special purpose vehicle 101 ) . Design of the Panzer I began in 1932 and mass production in 1934 . Intended only as a training tank to introduce the concept of armored warfare to the German Army , the Panzer I saw combat in Spain during the Spanish Civil War , in Poland , France , the Soviet Union and North Africa during the Second World War , and in China during the Second Sino - Japanese War . Experiences with the Panzer I during the Spanish Civil War helped shape the German armored corps ' invasion of Poland in 1939 and France in 1940 . By 1941 , the Panzer I chassis design was used for production of tank destroyer s and assault gun s . There were attempts to upgrade the Panzer I throughout its service history , including by foreign nations to extend the design lifespan . It continued to serve in the armed forces of Spain until 1954 . The Panzer I ' s performance in combat was limited by its thin armor and light armament of two general purpose machine gun s . As a design intended for training , the Panzer I was not as capable as other light tanks of the era , such as the T - 26 . Although weak in combat , it formed a large portion of Germany ' s tank strength in numbers and was used in all major campaigns between September 1939 and December 1941 . The small , vulnerable light tank would be surpassed in importance by better - known German tanks such as the Panzer IV , Panther , and Tiger . Nevertheless , the Panzer I ' s contribution to the early victories of Nazi Germany during the Second World War was significant . Development history . The post - World War I Treaty of Versailles of 1919 prohibited the design , manufacture and deployment of tank s within the Reichswehr . Paragraph Twenty - four of the treaty provided for a 100 , 000 - mark fine and imprisonment of up to six months for anybody who " [ manufactured ] armoured vehicles , tanks or similar machines , which may be turned to military use " . Despite the manpower and technical limitations imposed upon the German Army by the Treaty of Versailles , several Reichswehr officers established a clandestine General Staff to study World War I and develop future strategies and tactics . Although at first the concept of the tank as a mobile weapon of war met with apathy , German industry was silently encouraged to look into tank design , while quiet cooperation was undertaken with the Soviet Union . There was also minor military cooperation with Sweden , including the extraction of technical data that proved invaluable to early German tank design . As early as 1926 various German companies , including Rheinmetall and Daimler - Benz , produced a single prototype armed with a large 75 - millimeter cannon ( the " Großtraktor " , " large tractor " , was so codenamed to veil the true purpose of the vehicle ) . Only two years later prototypes of the new " Leichttraktor " ( " light tractor " ) , were produced by German companies , armed with 37 - millimeter KwK L / 45 guns . The " Großtraktor " was later put into service for a brief period with the 1 Panzer Division ; the " Leichttraktor " remained in testing until 1935 . In the late 1920s and early 1930s German tank theory was pioneered by two figures : General Oswald Lutz and his chief of staff , Lieutenant Colonel Heinz Guderian . Guderian became the more influential of the two and his ideas were widely publicized . Like his contemporary Sir Percy Hobart , Guderian initially envisioned an armored corps ( " panzerkorps " ) composed of several types of tanks . This included a slow infantry tank , armed with a small - caliber cannon and several machine guns . The infantry tank , according to Guderian , was to be heavily armored to defend against enemy anti - tank guns and artillery . He also envisioned a fast breakthrough tank , similar to the British cruiser tank , which was to be armored against enemy anti - tank weapons and have a large 75 - millimeter ( 2 . 95 in ) main gun . Lastly , Germany would need a heavy tank , armed with a massive 150 - millimeter ( 5 . 9 in ) cannon to defeat enemy fortifications , and even stronger armor . Such a tank would require a weight of 70 to 100 tonnes and was completely impractical given the manufacturing capabilities of the day . Soon after rising to power in Germany , Adolf Hitler approved the creation of Germany ' s first panzer divisions . Simplifying his earlier proposal , Guderian suggested the design of a main combat vehicle which would be developed into the Panzer III , and a breakthrough tank , the Panzer IV . No existing design appealed to Guderian . As a stopgap , the German Army ordered a preliminary vehicle to train German tank crews . This became the Panzer I . The Panzer I ' s design history can be traced to 1932 ' s " Landswirtschaftlicher Schlepper " ( La S ) ( Agricultural Tractor ) armored fighting vehicle . The La S was intended not just to train Germany ' s panzer troops , but to prepare Germany ' s industry for the mass production of tanks in the near future : a difficult engineering feat for the time . In July 1932 , Krupp revealed a prototype of the " Landswerk Krupp A " , or LKA , with a sloped front glacis plate and large central casemate , a design heavily influenced by the British Carden Loyd tankette . The tank was armed with two obsolescent 7 . 92 - millimeter ( . 312 in ) MG - 13 Dreyse machine guns . Machine guns were known to be largely useless against even the lightest tank armor of the time , restricting the Panzer I to a training and anti - infantry role by design . A mass - produced version of the LKA was designed by a collaborative team from Daimler - Benz , Henschel , Krupp , MAN , and Rheinmetall , exchanging the casemate for a rotating turret . This version was accepted into service after testing in 1934 . Although these tanks were referred to as the La S and LKA well beyond the start of production , its official designation , assigned in 1938 , was " Panzerkampfwagen I Ausführung . A " ( ' model A ' or , more accurately , ' batch A ' ) . The first fifteen tanks , produced between February and March 1934 , did not include the rotating turret and were used for crew training . Following these , production was switched to the combat version of the tank . The Ausf . A was under - armored , with steel plate of only 13 millimeters ( 0 . 51 in ) at its thickest . The tank had several design flaws , including suspension problems which made the vehicle pitch at high velocities , and engine overheating . The driver was positioned inside the chassis and used conventional steering levers to control the tank , while the commander was positioned in the turret where he also acted as gunner . The two crew members could communicate by means of voice tube . Machine gun ammunition was stowed in five bins , containing various numbers of 25 - round magazines . Author Lucas Molina Franco suggests that 833 " Panzerkampfwagen I Ausf . A " tanks were built in total , while authors Bryan Perrett offers the number of 300 and Terry Gander 818 units . Many of the problems in the Ausf . A were corrected with the introduction of the Ausf . B . The engine was replaced by the water - cooled , six - cylinder Maybach NL 38 TR , developing , and the gearbox was changed to a more reliable model . The larger engine required the extension of the vehicle ' s chassis by 40 cm ( 16 in ) , and this allowed the improvement of the tank ' s suspension , adding an additional bogie wheel and raising the tensioner . The tank ' s weight increased by 0 . 4 tons . Production of the Ausf . B began in August 1935 and finished in early 1937 — Franco writes 840 were constructed , but notes that only 675 of these were combat models , while Perrett suggests a total number of 1 , 500 ( offsetting the low number of Ausf . A he proposes ) and Gander a total of 675 . Sister tanks . Two more combat versions of the Panzer I were designed and produced between 1939 and 1942 . By this stage the design concept had been superseded by medium and heavy tanks and neither variant was produced in sufficient numbers to have a real impact on the progress of the war . These new tanks had nothing in common with either the Ausf . A or B except name . One of these , the Panzer I Ausf . C , was designed jointly between Krauss - Maffei and Daimler - Benz in 1939 to provide an amply armored and armed reconnaissance light tank . The Ausf . C boasted a completely new chassis and turret , a modern torsion - bar suspension and five interleaved roadwheels . It also had a maximum armor thickness of 30 millimeters ( 1 . 18 in ) , over twice that of either the Ausf . A or B , and was armed with a 20 - millimeter ( 0 . 78 in ) EW 141 autocannon . Forty of these tanks were produced , along with six prototypes . Two tanks were deployed to 1 Panzer Division in 1943 , and the other thirty - eight were deployed to the LVIII Panzer Reserve Corps during the Normandy landings . The second vehicle , the Ausf . F , was as different from the Ausf . C as it was from the Ausf . A and B . Intended as an infantry support tank , the Panzer I Ausf . F had a maximum armour thickness of 80 millimeters ( 3 . 15 in ) and weighed between 18 and 21 tonnes . The Ausf . F was armed with two 7 . 92 - millimeter MG - 34 s . Thirty were produced in 1940 , and a second order of 100 was later canceled . In order to compensate for the increased weight , a new Maybach HL45 Otto engine was used , allowing a maximum road speed of 25 kilometers per hour ( 15 . 5 mph ) . Eight of the thirty tanks produced were sent to the 1 Panzer Division in 1943 and saw combat at the Battle of Kursk . The rest were given to several army schools for training and evaluation purposes . Combat history . Spanish Civil War . On 18 July 1936 , war broke out on the Iberian peninsula as Spain dissolved into a state of civil war . After the chaos of the initial uprising , two sides coalesced and began to consolidate their position — the Popular front ( the Republicans ) and the Spanish Nationalist front . In an early example of a proxy war , both sides quickly received support from other countries , most notably the Soviet Union and Germany , who wanted to test their tactics and equipment . The first shipment of foreign tanks , fifty Soviet T - 26 ' s , arrived on 15 October . The shipment was under the surveillance of the German Navy and Germany immediately responded by sending forty - one Panzer I ' s to Spain a few days later . This first shipment was followed by four more shipments of Panzer I Ausf . B ' s , with a total of 122 vehicles . The first shipment of Panzer I ' s was brought under the command of Lieutenant Colonel Wilhelm Ritter von Thoma in Gruppe Thoma ( also referred to as Panzergruppe Drohne ) . Gruppe Thoma formed part of Gruppe Imker , the ground formations of the German Condor Legion , who fought on the side of Franco ' s Nationalists . Between July and October , a rapid Nationalist advance from Seville to Toledo placed them in position to take the Spanish capital , Madrid . The Nationalist advance and the fall of the town of Illescas to Nationalist armies on 18 October 1936 caused the government of the Popular Front ' s Second Republic , including President Manuel Azaña , to flee to Barcelona and Valencia . In an attempt to stem the Nationalist tide and gain crucial time for Madrid ' s defence , Soviet armor was deployed south of the city under the command of Colonel Krivoshein before the end of October . At this time , several T - 26 tanks under the command of Captain Paul Arman were thrown into a Republican counterattack directed towards the town of Torrejon de Velasco in an attempt to cut off the Nationalist advance north . This was the first tank battle in the Spanish Civil War . Despite initial success , poor communication between the Soviet Republican armor and Spanish Republican infantry caused the isolation of Captain Arman ' s force and the subsequent destruction of a number of tanks . This battle also marked the first use of the molotov cocktail against tanks . Ritter von Thoma ' s Panzer Is fought for the Nationalists only days later on 30 October , and immediately experienced problems . As the Nationalist armor advanced , it was engaged by the Commune de Paris battalion , equipped with Soviet BA - 10 armored cars . The 45 - millimeter ( 1 . 7 in ) gun in the BA - 10 was more than sufficient to knock out the poorly armored Panzer I at ranges of over 500 meters ( 550 yd ) . Although the Panzer I would participate in almost every major Nationalist offensive of the war , the Nationalist army began to deploy more and more captured T - 26 tanks to offset their disadvantage in protection and firepower . At one point , von Thoma offered up to 500 pesetas for each T - 26 captured . Although the Panzer I was initially able to knock out the T - 26 at close range — 150 meters ( 165 yd ) or less — using an armor - piercing 7 . 92 millimeter bullet , the Republican tanks began to engage at ranges where they were immune to the machine guns of the Panzer I . The Panzer I was upgraded in order to increase its lethality . On 8 August 1937 , Major General García Pallasar received a note from Generalísimo Francisco Franco which expressed the need for a Panzer I ( or " negrillo " , as their Spanish crews called them ) with a 20 - millimeter gun . Ultimately , the piece chosen was the Breda Model 1935 , due to the simplicity of the design over competitors such as the German Flak 30 . Furthermore , the 20 mm Breda was capable of perforating 40 millimeters of armor at 250 meters ( 1 . 57 in at 275 yd ) , which was more than sufficient to penetrate the frontal armor of the T - 26 . Although originally forty Italian CV . 35 light tanks were ordered with the Breda in place of their original armament , this order was subsequently canceled after it was thought adaptation of the same gun to the Panzer I would yield better results . Prototypes were ready by September 1937 and an order was placed after successful results . The mounting of the Breda in the Panzer I required the original turret to be opened at the top and then extended by a vertical supplement . Four of these tanks were finished at the Armament Factory of Seville , but further production was canceled as it was decided sufficient numbers of Republican T - 26 tanks had been captured to fulfill the Nationalist leadership ' s request for more lethal tanks . The Breda modification was not particularly liked by German crews , as the unprotected gap in the turret , designed to allow the tank ' s commander to aim , was found to be a dangerous weak point . In late 1938 , another Panzer I was sent to the Armament Factory of Seville in order to mount a 45 mm gun , captured from a Soviet tank ( a T - 26 or BT - 5 ) . A second was sent sometime later in order to exchange the original armament for a 37 - millimeter Maklen anti - tank gun , which had been deployed to Asturias in late 1936 on the Soviet ship A . Andreiev . It remains unknown to what extent these trials and adaptations were completed , although it is safe to assume neither adaptation was successful beyond the drawing board . Second World War . During the initial campaigns of the Second World War , Germany ' s light tanks , including the Panzer I , formed the bulk of its armored strength . In March 1938 , the German Army marched into Austria , experiencing a mechanical breakdown rate of up to thirty percent . However , the experience revealed to Guderian several faults within the German " Panzerkorps " and he subsequently improved logistical support . In October 1938 , Germany occupied Czechoslovakia ' s Sudetenland , and the remainder of the country in March 1939 . The capture of Czechoslovakia allowed several Czech tank designs , such as the Panzer 38 ( t ) , and their subsequent variants and production , to be incorporated into the German Army ' s strength . It also prepared German forces for the invasion of Poland . Poland and the campaign in the west . On 1 September 1939 , Germany invaded Poland using seventy - two divisions ( including 16 reserve infantry divisions in OKH reserves ) , including seven panzer divisions ( 1 . , 2 . , 3 . , 4 . , 5 . , 10 . , " Kempf " ) and four light divisions ( 1 . , 2 . , 3 . , 4 . ) . Three days later , France and Britain declared war on Germany . The seven panzer and four light divisions were arrayed in five armies , forming two army groups . The battalion strength of the 1 Panzer Division included no less than fourteen Panzer I ' s , while the other six divisions included thirty - four . A total of about 2 , 700 tanks were available for the invasion of Poland , but only 310 of the heavier Panzer III and IV tanks were available . Furthermore , 350 were of Czech design — the rest were either Panzer I ' s or Panzer II s . The invasion was swift and the last Polish pockets of resistance surrendered on 6 October . The entire campaign had lasted five weeks ( with help of the Soviet forces which attacked on 17 September ) , and the success of Germany ' s tanks in the campaign was summed up in response to Hitler on 5 September : when asked if it had been the dive bomber s who destroyed a Polish artillery regiment , Guderian replied , " No , our panzers ! " The Poles suffered almost 190 , 000 casualties ( including around 66 , 300 killed ) in the campaign , the Germans around 55 , 000 ( including around 35 , 000 wounded ) . However , some 832 tanks ( including 320 PzI , 259 PzII , 40 Pz III , 76 PzIV , 77 Pz35 ( t ) , 13 PzBef III , 7 PzBef 38 ( t ) , 34 other PzBef and some Pz38 ( t ) ) were lost during the campaign , approximately 341 of which were never to return to service . This represented about a third of Germany ' s armor deployed for the Polish campaign . During the campaign no less than a half of Germany ' s tanks were unavailable due to maintenance issues or enemy action , and of all tanks , the Panzer I proved the most vulnerable to Polish anti - tank weapons . Furthermore , it was found that handling of armored forces during the campaign left much to be desired . During the beginning of Guderian ' s attack in northern Poland , his corps was held back to coordinate with infantry for quite a while , preventing a faster advance . It was only after Army Group South had its attention taken from Warsaw at the Battle of Bzura that Guderian ' s armor was fully unleashed . There were still lingering tendencies to reserve Germany ' s armor , even if in independent divisions , to cover an infantry advance or the flanks of advancing infantry armies . Although tank production was increased to 125 tanks per month after the Polish Campaign , losses forced the Germans to draw further strength from Czech tank designs , and light tanks continued to form the majority of Germany ' s armored strength . Months later , Panzer Is participated in Operation Weserübung — the invasion of Denmark and Norway . Despite its obsolescence , the Panzer I was also used in the invasion of France in May 1940 . Of 2 , 574 tanks available for the campaign , no fewer than 523 were Panzer I ' s . Furthermore , there were only 627 Panzer IIIs and IVs . At least a fifth of Germany ' s armor was composed of Panzer I ' s , while almost four - fifths was light tanks of one type or another , including 955 Panzer II , 106 Czech Panzer 35 ( t ) , and 228 Panzer 38 ( t ) . For their defense , the French boasted up to 4 , 000 tanks , including 300 Char B1 , armed with a 47 - millimeter ( 1 . 7 in ) gun in the turret and a larger 75 - millimeter ( 2 . 95 in ) low - velocity gun in the hull . The French also had around 250 Somua S - 35 , widely regarded as one of the best tanks of the period , armed with the same 47 millimeter main gun and protected by almost 55 millimeters ( 2 . 17 in ) of armor at its thickest point . Nevertheless , the French also deployed over 3 , 000 light tanks , including about 500 World War one - vintage FT - 17 s . The two main advantages German armor enjoyed were radios allowing them to coordinate faster than their British or French counterparts and superior tactical doctrine . North Africa and campaigns in the east . Italian setbacks in Egypt and their colony of Libya caused Hitler to dispatch aircraft to Sicily , and a blocking force to North Africa . This blocking force was put under the command of Lieutenant General Erwin Rommel and included the motorized 5th Light Division and the 15th Panzer Division . This force landed at Tunis on 12 February 1941 . Upon arrival , Rommel had around 150 tanks , about half Panzer III and IV . The rest were Panzer I ' s and IIs , although the Panzer I was soon replaced . On 6 April 1941 , Germany attacked both Yugoslavia and Greece , with fourteen divisions invading Greece from neighboring Bulgaria , which by then had joined the Tripartite Pact . The invasion of Yugoslavia included no less than six panzer divisions , which still fielded the Panzer I . Yugoslavia surrendered 17 April 1941 , and Greece fell on 30 April 1941 . The final major campaign in which the Panzer I formed a large portion of the armored strength was " Operation Barbarossa " , 22 June 1941 . The 3 , 300 German tanks included about 410 Panzer I ' s . By the end of the month , a large portion of the Red Army found itself trapped in the Minsk pocket , and by 21 September Kiev had fallen , thereby allowing the Germans to concentrate on their ultimate objective , Moscow . Despite the success of Germany ' s armor in the Soviet Union , between June and September most German officers were shocked to find their tanks were inferior to newer Soviet models , the T - 34 and Kliment Voroshilov ( KV ) series . Army Group North quickly realized that none of the tank guns currently in use by German armor could penetrate the thick armor of the KV - 1 . The performance of the Red Army during the Battle of Moscow and the growing numbers of new Soviet tanks made it obvious the Panzer I was not suitable for this front . Some less battle - worthy Panzer I ' s were tasked with towing lorries through mud to alleviate logistics problems at the front . Foreign service . After Germany , Spain fielded the largest number of Panzer I tanks . A total of 122 were exported to Spain during the Spanish Civil War , and , as late as 1945 , Spain ' s Brunete Armored Division fielded 93 . The Panzer I remained in use in Spain until aid arrived from the United States in 1954 when they were replaced by the relatively modern M47 Patton . Between 1935 and 1936 , an export version of the Panzer I Ausf . B , named the L . K . B . ( " Leichte Kampfwagen B " ) , was designed for export to Bulgaria . Modifications included up - gunning to a 20 - millimeter gun and fitting a Krupp M 311 V - 8 gasoline engine . Although three examples were built , none were exported to Bulgaria , although a single Panzer I Ausf . A had previously been sold . In 1937 , around ten Ausf . As were sold to China during a period of Sino - German cooperation , which were used in the Battle of Nanjing by the 3rd Armored Battalion . A final order was supplied to Hungary in 1942 , totalling eight Ausf . B ' s and six command versions . These were incorporated into the 1st Armored Division and saw combat in late 1942 . Variants . Between 1934 and the mid 1940s several variants of the Panzer I were designed , especially during the later years of its combat history . Because they were obsolescent from their introduction , incapable of defeating foreign armor , and outclassed by newer German tanks , the Panzer I chassis were increasingly repurposed as tank destroyer s and other variants . One of the most well known variants was the " Panzerbefehlswagen " ( " small armored command vehicle " ) , built on the Ausf . A and Ausf . B chassis — 200 of these were manufactured . The Panzer I Ausf . B chassis was also used to build the German Army ' s first tracked tank destroyer , the Panzerjäger I . This vehicle was armed with a Czech 47 - millimeter ( 1 . 85 in ) anti - tank gun .