During the First World War, Britain came under attack from the air, putting civilians in the firing line for the very first time.
At the start of the war, Britain was ill-prepared to deal with the threat from enemy airships and aircraft. Traditionally its home defence focussed on defending the coastline rather than its airspace and with most of the Royal Flying Corps (RFC) operating overseas, few aircraft remained to defend Britain.
The Underworld

Between May 1917 and May 1918 more that 300,000 people used the tube to shelter from German aeroplane attacks. That was double the amount of people that were regularly sheltering in the tube during the height of the London Blitz in September 1940.
The first aerial threat came from German airships called Zeppelins. At 11,000 feet, Zeppelins could turn off their engines, drifting silently to carry out surprise attacks. Successive damaging Zeppelin attacks in 1915 and 1916 caused public outcry and government embarrassment.
To counter the threat, street lights were dimmed and guns, searchlights, and observers were mobilised. Some RFC and Royal Naval Air Service squadrons were recalled, and defence switched from anti-aircraft guns to aeroplanes. Incendiary ammunition for aircraft was developed for bringing down the airships.
Letter concerning the burning of a Zeppelin
A letter from schoolboy Patrick Blundstone to his father in London, describing the destruction of a Zeppelin near Cuffley.
A section of the letter reads: "Please don't be alarmed, all is well that ends well, (and this did for us). We are all quite safe."
In June 1917, the first air raid on Britain by huge Gotha bomber aircraft took place. To meet this latest threat, new tactics in aerial combat were developed. Wireless communication, coupled with sophisticated observation and reporting of enemy movements, enabled fighters to be despatched to meet the bombers. Anti-aircraft fire and barrage balloons also forced enemy aircraft higher, compromising their bombing accuracy. By May 1918, over 60 Gothas had been destroyed and the aerial threat to Britain was effectively over.