World War II in Europe had begun on Friday 1 September 1939 when German forces
invaded Poland. JG 51, under the command of
Oberst Werner Mölders, was preparing for
Operation Barbarossa, the German invasion of the Soviet Union which was launched on 22 June 1941. On 29 June, Brendel claimed his first aerial victory. On 1 July, he was promoted to
Leutnant (second lieutenant) and two days later he was awarded the
Iron Cross 2nd Class (). Brendel then flew a number of
ground support missions, was awarded the Iron Cross 1st Class () on 21 April 1942. On 8 December, he claimed his 10th victory on his 225th combat mission. He claimed his 20th victory on 24 February 1943 and received the
Honor Goblet of the Luftwaffe () on 15 March 1943. On 25 May, Brendel was appointed
Staffelkapitän (squadron leader) of JG 51s 1.
Staffel (1st squadron), replacing
Oberleuntant (First Lieutenant) Hans Boos who had been killed in a
mid-air collision on 21 April. His number of aerial victories claimed increased to 30 on 5 May, and on 17 May he was awarded the
German Cross in Gold (). On 10 June, Brendel claimed his 40th opponent shot down and was promoted to
Oberleuntant on 1 July. On the first day of the
Battle of Kursk, 5 July 1943, Brendel claimed two
Ilyushin Il-2 ground-attack aircraft shot down on the northern flank of the attack. His wingman,
Unteroffizier Oskar Romm was credited with the destruction of a third Il-2. The next day, Brendel led his 1.
Staffel in an attack against 15
Douglas A-20 Havoc bombers from the 221 Bomber
Aviation Division. Brendel claimed one bomber destroyed but the fighter escort from 282 Fighter Aviation Division successfully engaged the German fighters. Brendel became an "
ace-in-a-day" for the first time on 12 July 1943, claiming aerial victories 53 to 57. On 28 July, Brendel was shot down and wounded in his
Focke-Wulf Fw 190 A-6 (
Werknummer' 470002—factory number) by Soviet anti artillery behind enemy lines. He managed to return to German held territory. On 1 October 1943, he was promoted to
Hauptman with a rank age dated to 1 April 1944. On 22 November, Brendel claimed six aircraft shot down on his 551st combat mission, taking his total to 101 aerial victories. For this achievement he was awarded the
Knight's Cross of the Iron Cross () that day. He was the 60th Luftwaffe pilot to achieve the century mark.
Group commander On 29 July 1944, Brendel claimed a
Yakovlev Yak-9 fighter shot down in the vicinity of
Białystok. His opponent may have been
Kapitan Vladimir Shchegolev from the
162nd Fighter Aviation Regiment, a fighter ace credited with 14 individual and three shared victories who was killed in action that day. On 1 September 1944, Brendel was appointed
Gruppenkommandeur (group commander) of III.
Gruppe of JG 51. He succeeded
Hauptmann Diethelm von Eichel-Streiber in this function who was transferred. Command of 1.
Staffel was briefly passed to
Leutnant Gerhard Mai before
Leutnant Kurt Dombacher was given command of the
Staffel on 10 September. Flying with III.
Gruppe on 16 October 1944, Brendel achieved his 150th victory on his 792nd combat mission. Following his 153rd victory, he was awarded the
Knight's Cross of the Iron Cross with Oak Leaves () on 14 January 1945, the 697th officer or soldier of the Wehrmacht so honored. He continued flying on the Eastern Front, claiming his 174th and 175th victory on 4 March 1945. End of March, he was ordered to Berlin where the presentation of the Oak Leaves was made at the
Reichsluftfahrtministerium (RLM— Ministry of Aviation) in Berlin by
Reichsmarschall Hermann Göring. On 18 February 1945, III.
Gruppe claimed six aerial victories during the battle of the
Courland Pocket, including four by Brendel. Two days later, he claimed three further victories. He claimed his last victory on the 25 April 1945, finishing the war with 189 victories and emerged as JG 51 highest claiming fighter pilot on the Eastern Front, including over 90 heavily armored
Ilyushin Il-2 ground-attack aircraft. ==Later life==