Following the Polish Campaign, all existing Light Divisions were reorganized into Panzer Divisions. 1st Light Division became 6th Panzer Division at Wuppertal, 2nd Light Division became 7th Panzer Division at Gera, 3rd Light Division became 8th Panzer Division at Cottbus and 4th Light Division became 9th Panzer Division. The newly formed 6th, 7th and 8th Panzer Divisions had their Panzer Regiment composed of three Panzer Abteilungs. 9th Panzer Division had its Panzer Regiment composed of two Panzer Abteilungs. In addition, each division had Rifle Brigade, Artillery Regiment (with two battalions), Anti-Tank Battalion, Anti-Aircraft Battalion, Engineer Battalion, Reconnaissance Battalion and Communications Battalion.
Previously existing 1st, 2nd, 3rd, 4th, 5th and 10th Panzer Division had their Panzer Regiment composed of four Panzer Abteilungs. Each Panzer Regiment as well as each Panzer Battalion had its own Command Company. This company was made up of five PzKpfw II tanks along with other vehicles and towed artillery pieces. Each Panzer Battalion was composed of three companies. 1st company was equipped with five PzKpfw IV and ten PzKpfw I and II. 2nd and 3rd company were equipped with five PzKpfw III and seventeen PzKpfw I and II. PzKpfw I and II tanks, when possible were replaced with PzKpfw III and IV tanks.
From April 9th to June 25th of 1940, Germany invaded and conquered Denmark, Norway in an operation codenamed "Weserubung", followed by Low Countries (Belgium and Holland) and France in an operation codenamed "Fall Gelb". All of the existing Panzer Division (1st to 10th Panzer Divisions) were involved in combat and were instrumental in the German victory.
Following German successes, new Panzer Divisions were formed and their number was doubled. In August of 1940, two new divisions were formed, 11th (at Neuhammer) and 14th Panzer Division (at Koningsbruck/Milowitz). In October, following new divisions were formed: 12th (at Stettin), 13th (at Vienna area), 18th (at Chemnitz) and 20th Panzer Division (at Erfurt). In November, more new division were formed: 15th (at Darmstadt/Landau), 16th (at Munster), 17th (at Augsburg) and 19th Panzer Division (at Hanover). All new divisions were formed based on Panzer Regiments of existing divisions and by reducing the number of tanks in those divisions approximately by half.
On February 11th of 1941, first elements of newly formed 5th Light Division from Wunsdorf were unloaded in Tripoli and had their debut engagement at El Agheila on February 24th. On March 11th, 5th Panzer Regiment of 3rd Panzer Regiment arrived in Tripoli to strengthen 5th Light Division followed by 15th Panzer Division (with 8th Panzer Regiment) on May 2nd of 1941. All those units formed DAK – Deutsches Afrika Korps (German Africa Corps), which fought in North Africa until May 13th of 1943, when it surrendered. 15th Panzer Division was reformed in Sicily in July of 1943 as 15th Panzer-Grenadier-Division.
In April and May of 1941, Germany turned towards the Balkans, invading and conquering Yugoslavia and Greece in an operation codenamed "Marita". Divisions involved in combat were 2nd, 5th, 8th, 9th, 11th and 14th Panzer Division.
On the Sunday morning of June 22nd of 1941, German Army along with other Axis forces attacked Soviet Union in an operation codenamed "Barbarossa". The invading force was divided into three Army Groups – von Leeb’s North, von Bock’s Centre and von Runstedt’ South. Army Group North had Hoepner’s 4th Panzer Group with 1st, 6th and 8th Panzer Division. Army Group Centre had Guderian’s 2nd Panzer Group with 3rd, 4th, 10th, 17th and 18th Panzer Division andHoth’s 3rd Panzer Group with 7th, 12th, 19th and 20th Panzer Division Army Group South had von Kleist’s 1st Panzer Group with 9th, 11th, 13th, 14th and 16th Panzer Division. Army Group North had Hoepner’s 4th Panzer Group with 1st, 6th and 8th Panzer Division. 18th Panzer Division was virtually wiped out in October of 1943 and was reformed as short-lived 18th Artillerie Division.
In August of 1941, 21st Panzer Division was formed from 5th Light Division in North Africa. It served in North Africa until its surrender on May 13th of 1943. It was reformed at Rennes in July of 1943 and saw service on the Western Front and from February of 1945 on the Eastern Front. 10th Panzer Division transferred to North Africa in December of 1942 was destroyed there never to be reformed.
In September of 1941, two new divisions were formed: 22nd Panzer Division in France and 23rd Panzer Division in Paris area. Both exclusively served on the Eastern Front. 22nd Panzer Division was virtually wiped out in November of 1942 and its remnants were renamed as "Kampfgruppe Brugsthaler" and later were incorporated into 6th and 23rd Panzer Division.
In November of 1941, 24th Panzer Division was formed at Stablack and it served exclusively on the Eastern Front.
In February of 1942, 25th Panzer Division was formed at Eberswalde and in Norway and from October of 1943, it served exclusively on the Eastern Front. In September of 1942, 26th Panzer Division was formed at Mons in Belgium and it served exclusively in Italy. In October of 1942, 27th Panzer Division was formed at Voronezh from elements of 22nd Panzer Division. It saw service on the Eastern Front and was disbanded in February of 1943, while its units were incorporated into 7th, 19th and 24th Panzer Division. In November of 1943, 130th Panzer-Lehr-Division was formed at Postdam and Bergen. It was saw little service in Hungary in early 1944 and after served on the Western Front.
In March of 1944, 116th Panzer Division "Windhund" was formed in France. It exclusively served on the Western Front. In mid-1944, two new units were formed, Fuhrer-Begleit-Panzer-Division and Fuhrer-Panzer-Grenadier-Division (at Cottbus). Both were formed from units at Hitler’s Headquarters. Fuhrer-Begleit-Panzer-Division saw service on the Western Front and from January of 1945 on the Eastern Front. Fuhrer-Panzer-Grenadier-Division saw service on the Eastern Front and from December of 1944 on the Western Front. In February of 1945, it returned to the Eastern Front. In September of 1944, Panzer Division "Feldherrnhalle" (also known as 1st Feldherrnhalle Panzer Division) was formed in Hungary based on 60th Panzer-Grenadier-Division "Feldherrnhalle". It was service on the Eastern Front.
In January of 1945, Panzer Division "Kurmark" was formed at Cottbus and it saw service on the Eastern Front. Also in January of 1945, Panzer Division "Feldherrnhalle 2" (also known as 2nd Feldherrnhalle Panzer Division) was formed outside Budapest from remnants of 13th Panzer Division and Panzer Division "Feldherrnhalle". It also saw service on the Eastern Front. In February of 1945, 232nd Panzer Division "Tatra" was raised in Slovakia, only to be destroyed in March of 1945 at Raab. In April of 1945, 233rd Panzer Division was formed at Aarhus/Viborg in Denmark and served as a security unit in Denmark.
"Grossdeutschland" was army’s premier elite panzer unit. It began its career in October of 1939 as Motorized Infantry Regiment to achieve the status of Panzer Corps in December of 1944. It served with distinction in France (1940) and on the Eastern Front (1941-45).
Number of divisions raised in February, March and April or even as late as early May of 1945 existed on mainly paper, since their strength was below that of a division. They included "Clausewitz", "Schlesien", "Courland", "Donau", "Holstein", "Muncheberg", "Nibelungen", "Westfalen", "Thuringen" and "Juterbog". Panzer Division "Clausewitz" / "Schlesien" was formed in February of 1945 as "Kampgruppe Holstein" from units of 233rd Panzer Division. Panzer Divisions "Donau", "Juterbog", "Muncheberg" and "Thuringen" were formed from school and training units as well as replacement personnel. Panzer Division "Courland" was formed from remnants of 14th Panzer Division and other units trapped in Courland. Panzer Division "Nibelungen" was formed from 38th SS-Panzer-Grenadier-Division "Nibelungen" and personnel at SS Junker School at Bad Tolz. Panzer Division "Westfalen" was probably in the process of forming when war ended. All of those divisions mostly saw action on the Eastern Front in the last days of the war.
Most of Panzer Divisions ended the war in April and May of 1945, while some were either destroyed, disbanded or surrendered earlier. Those include 10th and 15th Panzer Division in May of 1943 in North Africa, 18th Panzer Division in October of 1943 on the Eastern Front, 22nd Panzer Division in March of 1943 on the Eastern Front and 27th Panzer Division in February of 1943 on the Eastern Front.