At the start of the war, No. 4 Group, equipped with the Whitley, was the only trained night bomber force in the world. Alongside the Handley Page Hampden and the Vickers Wellington, the Whitley bore the brunt of the early fighting and saw action during the first night of the war, when they dropped propaganda leaflets over Germany. The propaganda flight made the Whitley the first aircraft of RAF Bomber Command to penetrate into Germany. Further propaganda flights would travel as far as Berlin, Prague, and Warsaw. On the night of 19/20 March 1940, in conjunction with multiple Hampdens, the Whitley conducted the first bombing raid on German soil, attacking the Hörnum seaplane base on the Island of Sylt. Following the Hörnum raid, Whitleys routinely patrolled the Frisian Islands, targeting shipping and seaplane activity.