Formed on 1 October 1937, the unit took part in the Polish Campaign, claiming six kills for three losses from 1–20 September 1939.

Herbert Ihlefeld, was its most successful ace, claiming 24 victories by September 1940 and earning the Ritterkreuz des Eisernen Kreuzes.

On 10 August 1940 future ace Hans-Joachim Marseille was assigned to I./LG 2, then based in Calais-Marck and flying sorties against England.

The excellent ground attack work carried out by its sister Gruppe (II./LG 2) had led to several fighter units, including I./LG 2, to also employing a Staffel of Bf 109s converted to fighter-bomber duties.

Over Yugoslavia, Leutnant Friedrich Geißhardt was to claim four JKRV Hawker Fury biplanes shot down.

Ihlefeld was rescued by German troops after eight days of arrest and returned to Germany to recover.

[3] During the Battle of Crete two Bf 109's Jabos of I./LG 2 were credited with sinking HMS Fiji with a loss of 276 crew.

[3] Following the successful conclusion of the Balkan campaign with the invasion of Crete the unit was withdrawn to Rumania for Operation Barbarossa.

The unit flew numerous low-level pin-point ground attack operations, and included within their rank as a Staffelkapitän future ace and General der Jagdflieger Oberleutnant Adolf Galland.

Operating 49 aircraft, the unit initially flew supporting attacks for the German paratroop assault on the Eben-Emael forts in May 1940.

The outstanding efforts of the Gruppe and its biplanes in what was a unique role for 1940 were recognised with the award of the Ritterkreuz des Eisernen Kreuzes to its commander and all three Staffelkapitäne.

The units most notable action took place at the Battle of Arras, during which a strong British armoured attack was repulsed.

(Schl)./LG 2 did not take part in the early phases Battle of Britain, and was mooted to convert into a 'true' dive-bomber unit equipped with the Junkers Ju 87.

With no direct Army offensive to support, the unit modified its type of operation, and through the winter and into the spring of 1941 kept up a series of sporadic nuisance raids against targets in England, suffering over a dozen aircraft losses.

The unit kept up a constant assault on the retreating Allied armies, supporting 12 Armee and its advance to the Corinth Canal.

Based at Praszniki in Poland near the Lithuanian border, II Gruppe, with 38 (37) Bf 109E and 22(17) Hs 123s, were tasked with attacking their share of the 60 Soviet airfields targeted on the opening day of the offensive, leading to the destruction of over 1,400 Soviet aircraft on the ground.

II Gruppe were transferred to the Northern sector around Lake Ladoga in August, and its impressive combat record again recognised by the award of Ritterkreuz des Eisernen Kreuzes to its four Staffelkaptäne; Oblts.

The II Gruppe Henschel's proved their rugged worth by launching a series of 'shuttle' missions against the counter-attacking Soviet forces in October, saving their own airfield from capture and inflicting heavy losses.

Gruppe was recalled to Werl in Germany to form the nucleus of the first ever Schlachtgeschwader (SG 1), and with Major Otto Weiß awarded the Oakleaves to the Knight's Cross.