The first German mass produced 109 fighter was the Bf-109E that has been mistakenly referred to as the Me-109. The Bf is the designator for the Bayerische Flugzeugwerke (BFW) (Bavarian Aircraft Works) that produced the original aircraft. In 1938 Messerschmitt took over BFW but throughout WWII German handbooks and documents referred to the aircraft as the Bf-109. By the end of 1939 the Bf-109E (Emil) had replaced all other 109 variants and equipped 13 Gruppens with 40 aircraft each. The Bf-109 was the main single-engine aircraft until the Fw-190 came along.
In December 1939 Romania ordered 50 Bf-109Es, 11 delivered in 1940 and the remaining 39 arriving one year later. These aircraft equipped the new Grupul 7 Vanatoare in time for them to take part in operation Barbarossa. But by mid 1941 the group had lost aircraft and was withdrawn to be replenished with 15 used German Bf-109E-7s. The unit returned to the front in time for the Battle of Stalingrad. Grupul 7 had 8 aircraft captured by the Soviets including Bf-109E3 No. 9 "Hai Fetito" flown by Lt. loan Di Cesare who is credited with 16 victories.