Following the Battle of France, the Luftwaffe started its attacks on Channel convoys as a prelude to the Battle of Britain. The primary task of JG 51 during this time was to provide fighter escort to these bomber missions. The commander of JG 51, "Oberst" Theo Osterkamp established a policy of unrestricted combat air patrol ("freie Jagd") of fighter "Staffeln" providing loose protection rather than close escort to the bombers, actively seeking out Royal Air Force fighters. On 7 July 1940 Oesau claimed one Spitfire.