Flying with Jagdgeschwader 52 (JG 52—52nd Fighter Wing), he claimed his first victory in July 1941 and his total rose steadily against Soviet Air Forces.

A month later, on 1 November, Barkhorn joined the military service in the Nazi German Luftwaffe as a Fahnenjunker (cadet) at the Air War School Klotzsche in Dresden.

[9] One of his flight instructors at the time was Franz Stigler who initially thought that Barkhorn was a bad pilot but later graduated him with good ratings.

[2] World War II in Europe began on Friday 1 September 1939 when German forces invaded Poland and Barkhorn was selected for specialized fighter pilot training.

[14] From 1 April until 30 June, Barkhorn was posted to Fliegerausbildungs-Regiment 10 (10th Aviators Training Regiment) based in Pardubitz, present-day Pardubice in the Czech Republic, as a company commander.

[17] Flying from Peuplingues on 27 September, Barkhorn for the first time had enemy contact on a combat air patrol across the English Channel during the Battle of Britain.

[25] During this time, Barkhorn flew many training and patrol missions on the Bf 109 F-2 until 20 April when he received the Front Flying Clasp of the Luftwaffe in Silver (Frontflugspange in Silber).

Fliegerkorps commanded by Generaloberst Wolfram Freiherr von Richthofen which supported the northern wing of Army Group Centre.

[30] Barkhorn claimed his first aerial victory by shooting down a Red Air Force Ilyushin DB-3 bomber on 2 July, flying his 120th combat sortie.

[40] He claimed his tenth and last aerial victory in 1941 on a meteorological reconnaissance mission (Wetterflug) over an I-61, an early German designation for a Mikoyan-Gurevich MiG-3 fighter,[36] on 30 November.

[44] The unit then moved to Wien-Schwechat on 24 April before flying to Zürichtal, present-day Solote Pole, a village near the urban settlement Kirovske in the Crimea.

[48] Barkhorn again became an "ace-in-a-day" on 19 July, flying four missions that day, he shot down six Soviet fighters taking his total to 51 aerial victories.

[50] On 24 July, Barkhorn transferred to an airfield named Nikolajewskaja, approximately 15 minutes flying time closer to front lines.

"Sweat was pouring off me just as though I had stepped out of the shower", he recalled: despite having a faster aircraft he was simply unable to get a bead on the Russian pilot.

His victims included Lieutenant Vasiliyev, and Hero of the Soviet Union Podpolkovnik Lev Shestakov of the 236 IAP Fighter Regiment.

On the train he met fellow JG 52 pilots Krupinski, Wiese and Hartmann, who were to receive the Oak Leaves to the Knight's Cross.

At the Führerhauptquartier they joined Kurt Bühligen, Horst Ademeit, Reinhard Seiler, Hans-Joachim Jabs, Dr. Maximilian Otte, Bernhard Jope and Hansgeorg Bätcher from the bomber force, and the Flak officer Fritz Petersen, all destined to receive the Oak Leaves.

[89] Returning to his unit, the psychological damage and combat stress on Barkhorn became apparent; sitting in his cockpit he became overcome with anxiety, and even when flying with friendly aircraft behind him he felt intense fear.

[90] On 1 January 1945, the Luftwaffe launched Operation Bodenplatte, a failed attempt to gain air superiority during the stagnant stage of the Battle of the Bulge.

[98] Five days later, a U.S. officer was looking for JV 44 pilots and Barkhorn, Krupinski, Karl-Heinz Schnell, Erich Hohagen and Waldemar Wübke stepped up.

[102] The first three Bundesluftwaffe pilots to receive jet aircraft training were Steinhoff, Barkhorn's former squadron commander during World War II, Dietrich Hrabak and Kurt Kuhlmey.

On 18 June 1956, Barkhorn, Krupinski and Wehnelt received the RAF aircrew brevet from Air Vice-Marshal George Philip Chamberlain in Stanford Park.

[106] In 1962, JaboG 31, under the command of Barkhorn, was the first unit to complete transition to the fighter bomber F-104 G. This event was to be celebrated at the Nörvenich Air Base on 20 June 1962.

The day before, the aerobatics team of the Bundesluftwaffe, led by their flight instructor Captain Jon Speer from the USAF, practiced the diamond formation for the celebration.

[111] On 1 January 1963, Barkhorn was transferred to the Führungsstab der Luftwaffe (German Air Staff), a department of the Federal Ministry of Defense.

[6] From October 1964 until November 1965, Barkhorn headed the six-man Bundesluftwaffe contingent of the Tripartite Kestrel Evaluation Squadron at RAF West Raynham, Norfolk, England.

At the conclusion of the evaluation, Barkhorn then accompanied the American contingent to the U.S., where he assisted in that nation's continuing trials of six of the Kestrels that had been shipped to the U.S. and renamed the XV-6A.

On 10 September 1969, with the permission of the President of Germany, he was given the temporary rank of Brigadegeneral (brigadier general), the official promotion followed on 14 May 1970, effective as of 1 April.

Steinhoff, who had advanced in career to Inspector of the Air Force, had defined a small group of second generation leaders, among them Krupinski, Rall, Gerhard Limberg and Friedrich Obleser.

However, Rall, who succeeded Steinhoff as Inspector of the Air Force in 1971, attested that Barkhorn lacked the toughness and ability to work under pressure required for a higher command position in the Bundesluftwaffe.