On 3 September 1914 the Admiralty was put in charge of the defence of the United Kingdom against air attack. Its strategy was to use its limited number of aircraft in attacks on airship bases rather than on defensive patrols.
A seaplane carrier raid was launched against the airship base near Cuxhaven on 25 December 1914. An attack on the Emden base was planned, but was postponed on 14 January 1915 because the weather was unsuitable for seaplanes.
Night attacks were expected in 1914, so some restrictions on lighting were introduced in London, Birmingham and coastal towns. These did not entail a full blackout because of the potential effect on road safety and business. Major thoroughfares and bridges had their lighting broken up and parks were given lights in order to stop enemy airmen using them to find their targets. Lights on public transport were reduced to the minimum and ones in shops shaded.
A Naval Corps of Anti-Aircraft Volunteers was established to man anti-aircraft guns, with recruitment starting on 9 October. However, there were so few guns that only London, Dover and Sheffield could be defended at first. The dockyards were so busy that it was decided that their lights would be put out only when a raid had been detected.
Guns and searchlights were deployed in ports as more became available, but the RN did not have enough men to man them. A conference on 16 October 1914 therefore decided that the army would responsible for the aerial as well as the land defence of defended ports, with the help of the aircraft of the Royal Naval Air Service. Once enemy aircraft or airships had crossed the coast it was up to the Admiralty to destroy them. The aircraft of the army’s Royal Flying Corps would be principally responsible for aiding the army in fighting an enemy invasion, but when available would help the RNAS in combating air raids. 
The first German air raids were carried out by aircraft. One dropped two bombs into the sea off Dover on 21 December. Three days later another dropped the first aerial bomb to land on British soil, also on Dover. The only damage was broken glass. Another aircraft appeared the next day. It was attacked by British anti-aircraft guns and pursued by three aircraft, but it ecaped.
The German navy had discussed using its airships to attack the UK in September 1914, but had decided that it did not then have enough Zeppelin airships to do so whilst carrying out the more important task of fleet reconnaissance. By 7 January 1915 it had 12 airships, and Admiral Friedrich von Ingenohl, the Commander-in-Chief of the High Seas Fleet, decided that four could be used to bomb the UK. The long nights of January and February were thought to be particularly suitable for airship raids. There was also a desire to act before the British repeated their raid on the airship sheds.
The intention was to attack military targets, with damage to historical buildings and private property being limited as far as possible. The German Admiralty thought that London was a military target, but Kaiser Wilhelm ordered that:
‘London itself not to be bombed at present; attacks are to be confined to dockyards, arsenal, docks (those near London also), and military establishments of a general nature, also Aldershot Camp, if there are no German prisoners there.’
The first date on which the weather was suitable was 19 January. Three Zeppelins set off between 9:00 am and 11:00 am. L6 (Oberleutnant Freiherr von Buttlar) had to turn back because of engine problems, but L3 (Kapitänleutnant Hans Fritz) and L4 (Kapitänleutnant Graf von Platen) arrived over the east coast of England at 8:00 pm.
Their target was Great Yarmouth. The authors of the British Naval Staff Memorandum note that it ‘seemed to exercise a curious fascination over the minds of those planning raids in Germany…in preference to more valuable objectives.’ It had been the target of a raid by surface ships on 3 November 1914. It was a defended port, so was a military target, but not an important one, so was most likely chosen for geographical rather than military reasons.
L3 crossed the coast at Winterton and turned south towards Yarmouth. Fritz reported being fired upon by anti-aircraft guns on the north side of the town, and dropped six 110 pound explosive and seven incendiary bombs from 4,900 feet. He then headed home, crossing the English coast at 8:27 pm and reaching Fühlsbüttel at 9:00 am on 20 January.
L4 made a navigational error and found herself over the small town of Sheringham around 8:35 pm. Von Platen dropped two bombs on it, before heading west and dropping one bomb on each of the villages of Thornham, Brancaster, Hunstanton, Heacham and Snettisham, He stated that his airship then found itself over a large town at a height of 820 feet. It was caught in searchlights and came under fire, so he dropped seven 110 pound explosive and one incendiary bombs. The town was King’s Lynn.
The British Naval Staff Monograph states that:
‘The firing and the searchlights which the airships reported they had been met with were entirely imaginary. Althoguh the British air stations had been warned at 8:40 pm, and L4 did not get clear of the Norflok coast until 12:30 am, January 20, no anti-aircraft action was taken either by guns of aeroplanes.’
It is difficult to see why an internal document, intended only for the use of RN officers and written in 1925, would lie, so it would appear that the Germans imagined the anti-aircraft fire.
Four British civilians were killed in the raid. Samuel Smith, the first person in Britain to be killed by aerial bombardment, and Martha Taylor in Yarmouth and 14 year old Percy Goate and Alice Gazely, a 26 year old war widow, in King’s Lynn. Three were injured in Yarmouth and 13 in King’s Lynn. This link includes pictures of the damage.
It is widely claimed, including by the Daily Mail and Gorleston & Great Yarmouth History websites linked in the previous paragraph, that the Kaiser forbade attacks on London because he did not want to risk injuring his relatives in the British Royal Family. However, this website notes that L4 flew over Sandringham, one of the Royal Family’s houses, leading to allegations at the time that it was a target of the raid, which it was not.
 Naval Staff Monograph (Historical) vol. xii, Home Waters part iii, November 1914 to the end of January 1915. pp. 173-74.
 Ibid., p. 169.
 Ibid., pp. 174-75; W. A. Raleigh, H. A. Jones, The War in the Air: Being the Story of the Part Played in the Great War by the Royal Air Force, 7 vols. (Oxford: Clarendon Press, 1922). vol. iii, p. 83-86.
 Raleigh, Jones, War in the Air, p. 89.
 Naval Staff vol. Xii. p. 175.
 Quoted in Ibid., p. 176.
 There are some differences in times and number of bombs dropped in various sources. The ones quoted here are from Ibid., pp. 176-77.
 Ibid., p. 177.