 While RAF bombing of Germany began almost immediately upon the outbreak of war, under the leadership of Air Chief Marshal Harris, these attacks became increasingly devastating from 1942 onward as new technology and greater numbers of superior aircraft became available.The RAF adopted night-time area bombing on German cities such as Hamburg and Dresden, and developed precision bombing techniques for specific operations, such as the "Dambusters" raid by No.617 Squadron, or the Amiens prison raid known as Operation Jericho.