The Gotha G series of bombers were the main German twin-engine bombers of World War I. Built by Gothaer Waggonfabrik, the first unsuccessful variant was the G.I. It had an unusual shape, with a fuselage upon the upper wing of the biplane, and only a small number were built. The next Gotha planes were completely different from G.I, and were similar to each other, the main difference being in the engines used. The most numerous types were the Gotha G.IV and G.V. Though its bomb load by modern standards is negligible, their effect on British morale and war effort was enormous. They replaced the vulnerable Zeppelins.

The bombing of Upper North Street School in Poplar has a particularly powerful emotional and political impact. 18 children died and 30 were injured in that attack, the school being one of many death sites on a raid delivered by a fleet of 18 Gotha bombers on June 13, 1917. Aircraft in this group also bombed Margate, Foulness Island, Shoeburyness, Greenwich, East Ham, Southwark and Dalston. 72 bombs fell within a mile of Liverpool Street station within 2 minutes. The death toll - including Poplar - reached 162 and another 432 people were injured, making the raid the most severe yet witnessed in Britain. The effectiveness of Britain's air defences were tragically exposed as all the Luftwaffe planes returned abroad to their bases. Some 92 British pilots had taken-off to seek the raiders but most never saw a Gotha; one was killed from enemy fire. The surprise and speed of the raid was such that the British War Cabinet convened the same afternoon to consider reports of the raid and met again on May 14 to discuss a response. As a result some RFC squadrons were recalled from France to improve the defence of Kent.

On July 7, 1917 a similar raid of some 20 Gothas approached London from the north and north west, 97 pilots ascended in RFC and RNAS aircraft and the City and east end of London suffered heavy bombing. 54 deaths and 190 injuries resulted, of which 10 fatalities and 55 injured were blamed on ack-ack fire from English units. One Gotha was brought down but another Cabinet meeting was immediately convened, reflecting the further shock of this audacious raid. Prior to these raids, women, children and other non-combatants presumed themselves to be relatively immune from direct military attacks. The rules of war seemed to have changed profoundly, perhaps forever.