During 1941, Mk II Hurricanes played an important air defence role when the Soviet Union found itself under threat from the approaching German Army, who were advancing across a broad front stretching from Leningrad and Moscow to the oil fields in the south. Britain's decision to aid the Soviets meant sending supplies by sea to the far northern ports, and as the convoys would need to sail within range of enemy air attack from the Luftwaffe based in neighbouring Finland, it was decided to deliver a number of Hurricane Mk IIBs, flying with Nos. 81 and 134 Squadrons of No. 151 Wing RAF, to provide protection. Twenty-four were transported on the carrier "Argus", arriving just off Murmansk on 28 August 1941, and another 15 crated aircraft on board merchant vessels. In addition to their convoy protection duties, the aircraft also acted as escorts to Russian bombers. (See "Operation Benedict".)