 Secondary objectives were to destroy aircraft production and ground infrastructure, to attack areas of political significance, and to terrorise the British people into seeking an armistice or surrender.The British date the battle from 10 July to 31 October 1940, which represented the most intense period of daylight bombing.German historians usually place the beginning of the battle in mid-August 1940 and end it in May 1941, on the withdrawal of the German bomber units in preparation for Operation Barbarossa, the campaign against the Soviet Union.