In April 1945, in the last days of World War II in Europe, Adolf Hitler appointed Greim commander-in-chief of the Luftwaffe (German air force) after Hermann Göring had been dismissed for treason.

[1] From 18 September 1906 to 6 July 1911, Greim attended the Bavarian Cadet Corps [de] (Bayerisches Kadettenkorps) on the Marsfeld in Munich and graduated with his Abitur (university entry qualification).

[3] During his officer training, he was posted to the Royal Bavarian 8th Field Artillery Regiment "Prinz Heinrich von Preußen" [de] (Königlich Bayerisches 8.

Feldartillerie-Regiment „Prinz Heinrich von Preußen“), a field artillery regiment of the 6th Royal Bavarian Division on 25 February 1913.

[7] When World War I started in August 1914, Greim's regiment was subordinated to the 6th Army under its commander-in-chief Generaloberst Rupprecht, Crown Prince of Bavaria.

During combat in the Bois d'Ailly (Ailly Wood), Greim earned the Iron Cross 2nd Class (Eisernes Kreuz 2.

On 10 August, Greim began his training as an aerial observer with the Feldflieger Abteilung 3b (FFA 3b—Field Flying Company 3b).

The departing cowling damaged his top wing, along with the lower left interplane strut, but Greim managed to land the machine successfully.

[19] By 1919, Greim had returned to Bavaria and rejoined his regiment (8th Bavarian Artillery) and was discharged from the Reichswehr on 31 March 1920 holding the rank of Hauptmann.

Heß was also a student in Munich and a former pilot during World War I who had occasionally flown under the command of Greim while both their units were based at Gosselies.

This was the key turning point in his career, as in 1920 he flew the up-and-coming German army propaganda instructor Adolf Hitler to Berlin as an observer of the failed Kapp Putsch.

Upon his return to Germany, Greim took part in the 1923 putsch; as a convinced Nazi, he "remained utterly committed to Hitler to the very end of the war".

[26] In 1924, Greim, together with Richard Walter, Robert Heibert and Werner Charlottenburg, was recruited by the Chiang Kai-shek government to help build a Chinese air force in Canton initially led by Sun Yat-sen.[27] Traveling by ship on the SS Trier, the pilots arrived in Hong Kong on 13 September.

[29] Around the turn of the year 1925/26, his wife Alice and son Hubert joined Greim in Canton, making the journey on the SS Coblenz.

[30] In early April 1927, Greim and his family left Canton, taking the Trans–Siberian Railway via Harbin, Moscow and Warsaw, arriving in Munich on 1 May 1927.

[31] In Moscow, Greim failed to help a longtime school and war friend, Josef Römer, with establishing contact to the Soviets.

[35] On 14 June 1935, Greim visited the Deutsche Forschungsanstalt für Segelflug (German Institute for Glider Research) based at the Griesheim Airfield near Darmstadt.

There, together with his former World War I comrade Johann Pütz, they made multiple flights on a Junkers Ju 52 to São Pedro da Aldeia and Santos.

After the end of the Polish campaign, von Greim became commander of the 5th Fliegerkorps (5th Air Corps) which participated in the Battle of Britain.

In February 1943, von Greim was given command of Luftflotte 6, which continued to support Army Group Centre in its operations.

He made a forced landing in his Messerschmitt Bf 109 G-4 trop (Werknummer 16069—factory number) near Tabarka and Aïn Draham when his aircraft had been hit by anti-aircraft artillery.

"[citation needed] On 24 April 1945, Oberst Nicolaus von Below implemented Hitler's order and instructed Greim to immediately travel to the Führerbunker in Berlin.

Initially they flew from the central Luftwaffe test facility airfield, the Erprobungsstelle Rechlin to Gatow (a district of south-western Berlin) in a Focke-Wulf Fw 190.

[43] Having landed in Gatow, they changed planes to fly to the Chancellery; however, their Fieseler Storch was hit by anti-aircraft fire over the Grunewald.

Greim was incapacitated by a bullet in the right foot, but Reitsch was able to reach the throttle and joystick to land on an improvised air strip in the Tiergarten, near the Brandenburg Gate.

Then Hitler promoted Greim from Generaloberst to Generalfeldmarschall (field marshal), making him the last German officer ever to achieve that rank and appointed him as commander-in-chief of the Luftwaffe, to replace Hermann Göring, whom he had recently dismissed in absentia for treason.

On 28 April, Hitler ordered Ritter von Greim to leave Berlin and had Reitsch fly him to Plön, so that he could arrest Heinrich Himmler on the charge of treason.