HMS E1 (laid down as HMS D9) was a British E class submarine

British E class submarine

The British E class submarines started out as improved versions of the British D class submarine. All of the first group and some of the second group were completed before the outbreak of World War I....

 built by Chatham Dockyard

Chatham Dockyard

Chatham Dockyard, located on the River Medway and of which two-thirds is in Gillingham and one third in Chatham, Kent, England, came into existence at the time when, following the Reformation, relations with the Catholic countries of Europe had worsened, leading to a requirement for additional...

 and cost £101,700. E1 was laid down on 14 February 1911. She was launched on 9 November 1912 and was commissioned on 6 May 1913. During World War I

World War I

World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

 she was part of the British submarine flotilla in the Baltic

British submarine flotilla in the Baltic

A British submarine flotilla operated in the Baltic Sea for three years during the First World War. The squadron of nine submarines was attached to the Russian Baltic Fleet. The main task of the flotilla was to prevent the import of iron ore from Sweden to Imperial Germany...

.

Service history

She worked with and reconnoitered the Skagerrak

Skagerrak

The Skagerrak is a strait running between Norway and the southwest coast of Sweden and the Jutland peninsula of Denmark, connecting the North Sea and the Kattegat sea area, which leads to the Baltic Sea.-Name:...

 as a prelude to sending submarines into the Baltic

Baltic Sea

The Baltic Sea is a brackish mediterranean sea located in Northern Europe, from 53°N to 66°N latitude and from 20°E to 26°E longitude. It is bounded by the Scandinavian Peninsula, the mainland of Europe, and the Danish islands. It drains into the Kattegat by way of the Øresund, the Great Belt and...

. Then on 15 October 1914, she and sailed from Gorleston

Gorleston

Gorleston-On-Sea, also known colloquially as Gorleston, is a settlement in Norfolk in the United Kingdom, forming part of the larger town of Great Yarmouth. Situated at the mouth of the River Yare it was a port town at the time of the Domesday Book. The port then became a centre of fishing for...

 in a successful attempt to penetrate the German defences and enter the Baltic. On 18 October 1914, E1 unsuccessfully attacked the armoured cruiser  in Kiel Bay. On 19 August 1915, she torpedoed and damaged the German battlecruiser (23,000 tons) during the Battle of the Gulf of Riga

Battle of the Gulf of Riga

The Battle of the Gulf of Riga was a World War I naval operation of the German High Seas Fleet against the Russian Baltic Fleet in the Gulf of Riga in the Baltic Sea in August 1915...

.

E1s service ended on 3 April 1918 outside Helsinki

Helsinki

Helsinki is the capital and largest city in Finland. It is in the region of Uusimaa, located in southern Finland, on the shore of the Gulf of Finland, an arm of the Baltic Sea. The population of the city of Helsinki is , making it by far the most populous municipality in Finland. Helsinki is...

, 1.5 nautical miles (2.8 km) off Harmaja

Harmaja

Harmaja is an island and a lighthouse outside Helsinki, south of the Suomenlinna sea fortress. The island has been functioning as a landmark since the 16th century. A landmark structure was built on the island in the 18th century and a light house in 1883. The first lighthouse was only 7.3 m high...

 Light in the Gulf of Finland

Gulf of Finland

The Gulf of Finland is the easternmost arm of the Baltic Sea. It extends between Finland and Estonia all the way to Saint Petersburg in Russia, where the river Neva drains into it. Other major cities around the gulf include Helsinki and Tallinn...

. She was scuttled by her crew, along with , , , , , and to avoid seizure by advancing German forces

Baltic Sea Division

The Baltic Sea Division was a 10,000 man German military unit commanded by Rüdiger von der Goltz. During the Finnish Civil War, in April 1918, it landed at Hanko and moved towards Helsinki and Lahti. The Baltic Sea Division quickly took back Helsinki from the Social Democrats of Finland, who had...

which had landed nearby.