as well as 8 destroyers and 10 submarines. However, Sweden lacked any true dreadnought-type warships, and, of the three heavy Sverige-class warships ordered before the war, only one was completed before the war's end (HSwMS Sverige, launched in 1915 and commissioned in 1917). The coastal defence branch of the Swedish armed forces, the Kustartilleriet (coastal artillery), fell within the purview of the navy, had a strength of 7,500 men in 1914 (roughly half of the Navy's total active strength of 15–16,000 officers and rating). Despite its name, the Kustartilleriet did not consist only of artillery units, but also included infantry regiments formed separately to those of the army, and included both mobile and static defence forces. The main weight of defending Swedish neutrality during the war fell on the Swedish navy. Air forces The Swedes began the war with relatively few aircraft in military service, with reconnaissance groups being formed in both the army and the navy. The Swedish navy's group was originally formed in 1911, when a single Blériot monoplane was gifted to the navy. In 1913 a special naval aviation corps, the "Marinens Flygväsende" (MFV) was founded in Stockholm, and by 1914 this had expanded to include, in addition to the Blériot, two Henri Farmans and a Donnet-Leveque flying boat, all of which were based at Oscar Frederiksborg. During the war the total Swedish strength was expanded to a few dozen aircraft, many of these being bought through private subscription. In 1916 fighter aircraft were added to Sweden's air forces. However, Sweden's airforces were lacking in experience, doctrine, and tactics, and it was not until 1926 that an independent airforce was established. Sweden and the naval war The mining of the Oresund Throughout the war Germany applied pressure on Sweden and Denmark to close the channels connecting the Baltic sea to the (Allied-dominated) North Sea to Allied warships. Whilst Denmark had given into this pressure and mined the Danish straits at the outbreak of the war, Sweden resisted demands that its side of the Øresund should be mined. Eventually Germany relented in return for a promise that Sweden's lighthouses in the Øresund would be switched off and markers showing the way through the channel would be removed if the Royal Navy was sighted in the sound. When Royal Navy submarines entered the Baltic through the sound in October 1914, the Germans demanded that the Swedes carry out their