During August 1940, when Britain undoubtedly had its back to the wall, Lord Portal announced the Air Staff's intention to re-equip the RAF's strategic bombing force solely with four-engined aircraft. This might appear to be a very ambitious aim, but only days earlier the RAF's first four-engined "heavy", the Short Stirling, had been delivered to 7 Sqn. The Handley Page Halifax was not far behind, bringing the idea of a heavy bomber force closer to reality.