Teseo Tesei (3 January 1909 – 26 July 1941) was an Italian naval officer, who invented the

human torpedo Human torpedoes or manned torpedoes are a type of diver propulsion vehicle on which the diver rides, generally in a seated position behind a fairing. They were used as secret naval weapons in World War II. The basic concept is still in use. ...

(called ''Maiale'', Italian for "pig") used by the ''

Regia Marina The , ) (RM) or Royal Italian Navy was the navy of the Kingdom of Italy () from 1861 to 1946. In 1946, with the birth of the Italian Republic (''Repubblica Italiana''), the changed its name to '' Marina Militare'' ("Military Navy"). Origin ...

'' during World War II.

Early life and education

Teseo Tesei was born in Marina di Campo

Elba Elba (, ; ) is a Mediterranean Sea, Mediterranean island in Tuscany, Italy, from the coastal town of Piombino on the Italian mainland, and the largest island of the Tuscan Archipelago. It is also part of the Arcipelago Toscano National Park, a ...

in 1909, the son of Ulisse Tesei and Rosa Carassale. After attending the ''Collegio degli Scolopi'' in

Florence Florence ( ; ) is the capital city of the Italy, Italian region of Tuscany. It is also the most populated city in Tuscany, with 362,353 inhabitants, and 989,460 in Metropolitan City of Florence, its metropolitan province as of 2025. Florence ...

, he entered the Livorno Naval Academy in 1931, where he distinguished himself for perseverance and inventiveness. He was commissioned as a

lieutenant A lieutenant ( , ; abbreviated Lt., Lt, LT, Lieut and similar) is a Junior officer, junior commissioned officer rank in the armed forces of many nations, as well as fire services, emergency medical services, Security agency, security services ...

and graduated from the Naval Engineering School in Naples in 1933.

Career

Tesei had several posts on both surface ships and submarines. He was a volunteer in the

Spanish Civil War The Spanish Civil War () was a military conflict fought from 1936 to 1939 between the Republican faction (Spanish Civil War), Republicans and the Nationalist faction (Spanish Civil War), Nationalists. Republicans were loyal to the Left-wing p ...

with the rank of captain. In 1929, Tesei had the idea for the manned torpedo, from the Italian device used to sink the Austrian battleship SMS ''Viribus Unitis'' during

World War I World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting to ...

. In 1931 he entered the

Naval Academy A naval academy provides education for prospective naval officers. List of naval academies See also

* Military academy {{Authority control Naval academies, Naval lists ...

Livorno Livorno () is a port city on the Ligurian Sea on the western coast of the Tuscany region of Italy. It is the capital of the Province of Livorno, having a population of 152,916 residents as of 2025. It is traditionally known in English as Leghorn ...

, where he showed his inventive capabilities. Together with Elios Toschi, he designed a

called ''Siluro a lenta corsa (SLC)'' ("Slow-Run Torpedo"), later nicknamed the ''Maiale'', Italian for "pig", because it proved to be difficult to steer. The SLC was extensively used in

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

by the Italian Navy and was used in the sinking of two British battleships in

Alexandria Alexandria ( ; ) is the List of cities and towns in Egypt#Largest cities, second largest city in Egypt and the List of coastal settlements of the Mediterranean Sea, largest city on the Mediterranean coast. It lies at the western edge of the Nile ...

. The British later developed their own manned torpedo model, called "Chariot", from one of his captured "Maiali". In 1936, with Angelo Belloni he designed the high-performance closed-circuit self-contained breathing apparatus that was used by the Italian underwater raiders during their WWII operations, and that heavily influenced the following German and British wartime rebreathers design. In 1938 he was one of the officers who organized the Decima Flottiglia MAS underwater raiders unit of the Italian Navy. On 21 August 1940, Tesei was the only survivor when the Italian submarine ''Iride'' was sunk.

Killed in action

On 26 July 1941, Tesei died in action during a manned torpedo attack on

Malta Malta, officially the Republic of Malta, is an island country in Southern Europe located in the Mediterranean Sea, between Sicily and North Africa. It consists of an archipelago south of Italy, east of Tunisia, and north of Libya. The two ...

(see Decima Flottiglia MAS#1941), for which he was posthumously awarded the Italian Gold Medal of Military Valour.

Legacy

The modern Italian commando frogmen group Comando Raggruppamento Subacquei ed Incursori Teseo Tesei (

COMSUBIN COMSUBIN (''Comando Raggruppamento Subacquei e Incursori "Teseo Tesei"''; Divers and Raiders Group Command "Teseo Tesei") is the Italian Navy's special operations unit. Italy was the first nation to use frogmen and human torpedoes. The Royal I ...

) is named after him.

References

*Historical Diving Times, pp 6–11, issue 39.

Bibliography

* Greene, Jack ''The Black Prince and the Sea Devils: The Story of Valerio Borghese and the Elite Units of the Decima Mas''. Da Capo Press. Cambridge/Mass., 2004 * Schofield, William. ''Frogmen First Battles''. New York, 2000 {{DEFAULTSORT:Tesei, Teseo 1909 births 1941 deaths Armed forces diving 20th-century Italian inventors Regia Marina personnel killed in World War II Italian underwater divers People from the Province of Livorno History of scuba diving