HMS Alcantara and SMS Greif dueling at close range during the Action of 29 February 1916.
Armed merchantman is a term that has come to mean a merchant ship equipped with guns, usually for defensive purposes, either by design or after the fact. In the days of sail, piracy and privateers, many merchantmen would be routinely armed, especially those engaging in long distance and high value trade. The most famous of this type were the East Indiamen able to defeat regular warships in battle (see Battle of Pulo Aura).
In more modern times, auxiliary cruisers were used offensively to disrupt trade chiefly during both World War I and World War II, particularly by Germany.
1 Pre-20th century
1.1 Development of auxiliary cruisers
2 20th century
2.1 Armed merchant cruisers
2.2 Auxiliary cruisers
3 21st century
4 Ship list
5 See also
7 External links
Main article: East Indiaman
East Indiamen of various European countries were heavily armed for their long journeys to the Far East. In particularly dangerous times, such as when the home countries were at war, a convoy system would be used whereby the ships were escorted by a warship. However, many East Indiamen also travelled on their own, and therefore were heavily armed in order to defend themselves against pirates and privateers. They also defended themselves against warships, scoring signal victories at the Battle of Pulo Aura and the Action of 4 August 1800. The British Royal Navy purchased several that it converted to ships of the line.
Development of auxiliary cruisers
In 1856, privateering (or seizure of a belligerent country’s merchant ships as a private enterprise) lost international sanction under the Declaration of Paris. From 1861–65 European countries built high speed ships to run the Union Blockade during the American Civil War. Some of these were armed and served as Confederate States Navy raiders.
Russia purchased three ships in 1878 of 6,000 long tons (6,100 t) armed with 6-inch (150 mm) guns for use as auxiliary cruisers for a Russian Volunteer Fleet. Germany and the United Kingdom responded to the precedent by asking their shipping companies to design fast steamers with provision for mounting guns in time of war.
In 1890 German and British shipyards built new civilian ships designed for wartime conversion, and France, Italy, Japan, Austria-Hungary, and the United States made simil