[1] Lang was credited with 173 aerial victories—144 on the Eastern Front, 29 on the Western Front—and one Soviet MTB sunk in 403 combat missions.

Lang was born on 14 January 1909 at Thalheim, now part of Fraunberg in the Isar region near Freising in Bavaria, Germany.

Prior to World War II, he qualified as a civil pilot and flew with Deutsche Luft Hansa.

[5] World War II in Europe began on Friday 1 September 1939 when German forces invaded Poland.

Following the outbreak of war, Lang served as a transport pilot with the Fliegerhorst Kompanie (Airfield Company) at Gablingen, flying missions to Norway, France, Crete and North Africa.

[8] Before the year's end, Lang's kill tally stood at over 100 victories, with a remarkable 72 scored around Kiev in just three weeks during October and November 1943.

[10] During the Battle of Kiev, Lang set an all-time world record of 18 aerial victories claimed from four combat missions in one day on 3 November 1943, making him aviation history's leading ace-in-a-day.

[2] On 9 April 1944, Oberleutnant (First Lieutenant) Lang was appointed Staffelkapitän of the 9./JG 54 (9th Squadron of the 54th Fighter Wing) engaged in Defence of the Reich on the Western Front.

Kromer had only led the Staffel for two days after its former commander, Oberleutnant Gerhard Loos, had been killed on 6 March.

[16] Also present at the ceremony were Anton Hafner, Otto Kittel, Günther Schack, Alfred Grislawski, Erich Rudorffer, Martin Möbus, Wilhelm Herget, Hans-Karl Stepp, Rudolf Schoenert, Günther Radusch, Otto Pollmann and Fritz Breithaupt, who all received the Oak Leaves on this date.

[17] When Allied forces launched Operation Overlord, the invasion of German-occupied Western Europe on 6 June, III.

The Gruppe flew its first missions on 7 June to the combat area east of Caen and the Orne estuary.

[19] On 9 July, he claimed three Royal Air Force (RAF) Supermarine Spitfires (victories 160–162)—no Spitfires were shot down this day: American historian Donald Caldwell noted that his claims were exaggerated but asserted Lang's ebullience, energy and drive made him an effective combat leader.

[24] On 3 September 1944, Emil Lang was killed in action when his Fw 190 A-8 (Werknummer 171 240—factory number) "Green 1" hit the ground and exploded in a field at Overhespen.

Flying at an altitude of 200 metres (660 ft), his wingman, Unteroffizier Hans-Joachim Borreck, called out P-47 Thunderbolts to their rear.

Lieutenant Darrell Cramer took a high deflection shot at the Focke-Wulf on the left, which fell upside down in a steep dive and crashed hard into the ground; this undoubtedly was Emil Lang.

Captain Lang possesses an exemplary concept of service, has initiative and talent for improvisation to a large degree, well rooted in the National Socialist ideas.

Jagdkorps (2nd Fighter Corps), Generalleutnant (Major General) Alfred Bülowius, concurred with the assessment.