 Complete the following phrase:  On Friday 1 September 1939 German forces invaded Poland which marked the beginning of World War II, and in June 1941, Germany invaded the Soviet Union which created the Eastern Front. In February 1943, I. Gruppe of JG 54 was equipped with the Focke-Wulf Fw 190 A-4 and engaged in the Siege of Leningrad. The combat area was predomitly in the east and southeast of Leningrad where Soviet forces had created a corridor to the city in 