German strategic bombing during World War I

As the First World War unfolded, aircraft, which had previously been dismissed by many as having little military value, began to prove their critics wrong. As a result of these initial experiences, the armed forces on both sides began to develop specialized types of combat aircraft. Not all of these concepts survived the test of combat. One such concept was that of a "battle-plane: " a large, heavily armed, multi-engined aircraft designed to be a fighter aircraft. The battle-planes proved to be unable to fight more manoeuvrable single seat fighters such as the German Fokker Eindecker, the British Airco DH.2 and the French Nieuport 11 but they did prove highly successful when they were fitted with bomb racks and pressed into service as medium bombers. In Germany, these battle-planes were assigned the designation "K" (Kampfflugzeug) but once they had been re-assigned to the bomber role they were assigned the designation "G" (Großflugzeug) to identify them as bombers.

Zeppelin bombings
The first Zeppelin raid on England took place in January 1915. From then until the end of World War I the German Navy and Army Air Services mounted over 50 bombing raids on the United Kingdom. These were generally referred to as "Zeppelin raids", although both Zeppelin and Schütte-Lanz airships were used. From the beginning the airships had the advantage of flying at a higher altitude than could be reached by defending aircraft or anti-aircraft fire, and could carry a significant bomb-load, but weather conditions and night flying conditions made navigation and therefore bombing accuracy difficult. Bombs could be dropped miles off target (one raid on London actually bombed Hull instead) and pin-point accuracy to hit military targets was impossible. The civilian casualties made the Zeppelins an object of hatred, widely dubbed “baby-killers”. The airships made 20 raids in 1915, mostly Navy, mostly Zeppelins, and dropped 37 tons of bombs, killing 181 and injuring another 455 people.

In 1916 improved defensive measures, including the introduction of incendiary bullets, made raids more hazardous, and several airships were destroyed. Newer classes of ships with improved ceilings restored the advantage, but led to further flying and navigation problems; oxygen was needed to fly at high altitude, and provision for an observation car, for bombing through clouds, reduced the bomb load. Nevertheless, in 1916 23 raids dropped 125 tons of bombs, killing 293 and injuring 691 people.

In September 1916 the Army abandoned raids by airship in favour of developing a heavier than air alternative, and May 1917 saw the first use of Gotha bomber aeroplanes against Britain. The Navy, under FK Peter Strasser, continued with airships, though there were only six in 1917 and four in 1918. The last Zeppelin raid on Britain took place in August 1918 when four ships bombed targets in the Midlands and the North of England. The raid also a saw the loss of Strasser when L70 was shot down in flames over the North Sea.

Zeppelins (airships) performed about 51 strategic bombing raids during World War I. These raids caused numerous civilian casualties, killing 557 and injuring another 1,358 people. More than 5,000 bombs were dropped on towns across Britain, causing £1.5 million in damage. 84 airships took part, of these 30 were lost, either shot down by enemy action or lost in accident. The raids, though disconcerting to civilian morale, were militarily ineffective.

Operation Türkenkreuz – the Gotha Raids
The "Gotha Raids" were specific to a phase of aeroplane bombing raids conducted by Germany into Great Britain during the First World War using Gotha Gv bombers.

In late 1916, Germany began planning a daylight bombing offensive against Britain called Operation Türkenkreuz. In anticipation of the campaign, Kagohl (Kampfgeschwader der Obersten Heeresleitung) 3 (also nicknamed the "England Geschwader"), comprising six Kastas (Kampfstaffel) under the command of Hauptmann Ernst Brandenburg was formed. By this time, Britain had succeeded in dealing with the Zeppelins' threat when six were destroyed over England. Taken together with the reduction in Zeppelin raids over the winter, by the spring of 1917 there was a general lessening of concern in the country over German air raids. This was not unanimous, as there continued to be calls in Parliament for retaliation against German military targets.

Due to increasing losses at the Western Front and a resurgence of unrestricted German submarine warfare, resources were moved from raid protection.

Politically, a long-standing problem with regard to the means of aircraft production had largely been resolved by early 1917. The result was an increase in the numbers of aero-engines being produced but this contributed to complacency regarding attack from the air in the period.

For German planners, the bombing of targets in Britain had been a long term goal. Shortages of suitable long-range aircraft, the distance of bases from the targets and the demands of the front had limited operations to occasional 'tip and run' raids which by the end of 1916 had killed 25 people. With the availability of the Gotha G.IV in March 1917, Germany had a suitable aircraft. Kagohl 3, now known informally as the Englandgeschwader operated from Sint-Denijs-Westrem and Gontrode in the Ghent area of German-occupied Belgium. British raids on these bases forced Kagohl 3 to move to Mariakerke and Oostakker. In March and April, the unit was equipped with the first batch of G.IV aircraft.

Early daylight Gotha raids
On 25 May 1917, Kagohl 3 sent 23 Gothas on a daylight raid on London. Two were forced to turn back over the North Sea due to mechanical difficulties. Cloud over London caused the remaining bombers to divert to secondary targets at the Channel port of Folkestone and the nearby Army camp at Shorncliffe. The raid resulted in 95 deaths and 195 injuries, mostly in the Folkestone area. In Shorncliffe, 18 soldiers (16 Canadian and two British) were killed and 90 were wounded. Nine Royal Naval Air Service (RNAS) Sopwith Pups engaged the returning bombers near the Belgian coast, shooting one down.

A second attack on 5 June 1917 was diverted to Sheerness in Kent but a third attack on 13 June resulted in the first daylight raid on London, causing 162 deaths and 432 injuries. Among the dead were 18 children killed by a bomb falling on a primary school in Poplar. This was the deadliest air raid of the war. No Gothas were lost. In 1938, Air Commodore Lionel Charlton described the raid as "the beginning of a new epoch in the history of warfare."

The reason for the relatively large numbers of casualties seems to have been ignorance as to the threat posed by aerial bombardment of a city in daylight. A Royal Flying Corps (RFC) pilot on leave recorded that: ''...Raids hadn't become a very serious thing and everybody crowded out into the street to watch. They didn't take cover or dodge.'' Lt Charles Chabot, 39 Squadron RFC.

As there had been little planning, early attempts to intercept the Gothas were ineffectual. Large numbers of British aircraft were put into the air but were unable to climb high enough to engage the bombers. Captain James McCudden was part of the engaging force of 92 aircraft in the London raid but due to the performance of his machine had no success in intercepting the force.

A further Gotha raid of 22 aircraft was made on 7 July 1917, resulting in 54 deaths and 190 injuries. Many of these casualties were caused by falling anti-aircraft shells. One hundred sorties were flown against the formation, resulting in one Gotha shot down and three damaged. Two fighters were shot down by the Gothas.

Between May and August 1917, Kagohl 3 carried out a further eight daylight raids over England, including three raids on London.

Further night raids
Beginning in September 1917, improved British air defences forced Kagohl 3 to abandon daylight raids. While night raids provided a measure of protection from interceptors and anti-aircraft fire, they greatly complicated navigation and landing. Many damaged aircraft limped back to their airfields, only to be lost in landing accidents.

In December 1917, Kagohl 3 was renamed Bogohl 3 (Bombengeschwader der Obersten Heeresleitung 3). Unlike other Bogohls, which consisted of three Bostas (Bombenstaffel), Bogohl 3 retained its original strength of six staffeln.

Heavy losses forced Bogohl 3 to stand down from combat operations in February 1918. On the night of 19 May 1918, the Gothas returned to England for the last and largest raid of the war. Bogohl 3 sent 38 Gothas against London but suffered heavy losses. Six Gothas were shot down by interceptors and anti-aircraft fire and a seventh aircraft was lost in a landing accident. After this raid, Gothas were restricted to tactical strikes along the Western Front.

Gothas carried out 22 raids on England, dropping 186830 lb of bombs for the loss of 61 aircraft.