The Blitz was a German bombing campaign against the United Kingdom in 1940 and 1941, during the Second World War. The term was first used by the British press and originated from the term "Blitzkrieg", the German word for 'lightning war'.
The Germans conducted mass air attacks against industrial targets, towns, and cities, beginning with raids on London towards the end of the Battle of Britain in 1940. By September 1940, the Luftwaffe had lost the Battle of Britain and the German air fleets were ordered to attack London, to draw RAF Fighter Command into a battle of annihilation. Adolf Hitler and Reichsmarschall Hermann Göring, commander-in-chief of the Luftwaffe, ordered the new policy on 6 September 1940. From 7 September 1940, London was systematically bombed by the Luftwaffe for 56 of the following 57 days and nights. Most notable was a large daylight attack against London on 15 September.
The Luftwaffe gradually decreased daylight operations in favour of night attacks to evade attacks by the RAF, and the Blitz became a night bombing campaign after October 1940. The Luftwaffe attacked the main Atlantic seaport of Liverpool in the Liverpool Blitz.