Investment is the military process of surrounding an enemy

fort A fortification (also called a fort, fortress, fastness, or stronghold) is a military construction designed for the defense of territories in warfare, and is used to establish rule in a region during peacetime. The term is derived from La ...

(or

town A town is a type of a human settlement, generally larger than a village but smaller than a city. The criteria for distinguishing a town vary globally, often depending on factors such as population size, economic character, administrative stat ...

) with

armed forces A military, also known collectively as armed forces, is a heavily armed, highly organized force primarily intended for warfare. Militaries are typically authorized and maintained by a sovereign state, with their members identifiable by a ...

to prevent entry or escape. It serves both to cut communications with the outside world and to prevent supplies and reinforcements from being introduced. A contravallation is a line of fortifications built by the attackers around the besieged fortification facing towards an enemy fort to protect the besiegers from sorties by its defenders and to enhance the

blockade A blockade is the act of actively preventing a country or region from receiving or sending out food, supplies, weapons, or communications, and sometimes people, by military force. A blockade differs from an embargo or sanction, which are ...

. The contravallation can be used as a base to launch assaults against the besieged city or to construct further earthworks nearer to the city. A circumvallation may be constructed if the besieging army is threatened by a field army allied to an enemy fort. It is a second line of fortifications outside the contravallation that faces away from an enemy fort. The circumvallation protects the besiegers from attacks by allies of the city's defenders and enhances the

of an enemy fort by making it more difficult to smuggle in supplies. Lines of contravallation and circumvallation generally consist of earthen ramparts and entrenchments that encircle the besieged city.

Antiquity

Thucydides Thucydides ( ; ; BC) was an Classical Athens, Athenian historian and general. His ''History of the Peloponnesian War'' recounts Peloponnesian War, the fifth-century BC war between Sparta and Athens until the year 411 BC. Thucydides has been d ...

notes the role circumvallation played in the

Sicilian Expedition The Sicilian Expedition was an Classical Athens, Athenian military expedition to Sicily, which took place from 415–413 BC during the Peloponnesian War between Classical Athens, Athens on one side and Sparta, Syracuse, Sicily, Syracuse and Co ...

and in the Spartan

siege A siege () . is a military blockade of a city, or fortress, with the intent of conquering by attrition, or by well-prepared assault. Siege warfare (also called siegecrafts or poliorcetics) is a form of constant, low-intensity conflict charact ...

Plataea Plataea (; , ''Plátaia'') was an ancient Greek city-state situated in Boeotia near the frontier with Attica at the foot of Mt. Cithaeron, between the mountain and the river Asopus, which divided its territory from that of Thebes. Its inhab ...

during the initial stages of the

Peloponnesian War The Second Peloponnesian War (431–404 BC), often called simply the Peloponnesian War (), was an Ancient Greece, ancient Greek war fought between Classical Athens, Athens and Sparta and their respective allies for the hegemony of the Ancien ...

in 429 BC.

Julius Caesar Gaius Julius Caesar (12 or 13 July 100 BC – 15 March 44 BC) was a Roman general and statesman. A member of the First Triumvirate, Caesar led the Roman armies in the Gallic Wars before defeating his political rival Pompey in Caesar's civil wa ...

in his '' Commentaries on the Gallic War'' describes his textbook use of the circumvallation to defeat the

Gauls The Gauls (; , ''Galátai'') were a group of Celts, Celtic peoples of mainland Europe in the Iron Age Europe, Iron Age and the Roman Gaul, Roman period (roughly 5th century BC to 5th century AD). Their homeland was known as Gaul (''Gallia''). Th ...

under their chieftain,

Vercingetorix Vercingetorix (; ; – 46 BC) was a Gauls, Gallic king and chieftain of the Arverni tribe who united the Gauls in a failed revolt against Roman Republic, Roman forces during the last phase of Julius Caesar's Gallic Wars. After surrendering to C ...

, at the Siege of Alesia in September 52 BC. During the Siege of Jerusalem, Titus and his Roman legions built a circumvallation, cutting down all trees within .

Middle Ages

Another example from the pre-modern period is the

Siege of Constantinople (717–718) In 717–718, Constantinople, the capital of the Byzantine Empire, was besieged by the Muslim Arabs of the Umayyad Caliphate. The campaign marked the culmination of twenty years of attacks and progressive Arab occupation of the Byzantine borde ...

. The

caliph A caliphate ( ) is an institution or public office under the leadership of an Islamic steward with Khalifa, the title of caliph (; , ), a person considered a political–religious successor to the Islamic prophet Muhammad and a leader of ...

of the Umayyad Empire took advantage of the violent anarchy in the

Byzantine Empire The Byzantine Empire, also known as the Eastern Roman Empire, was the continuation of the Roman Empire centred on Constantinople during late antiquity and the Middle Ages. Having survived History of the Roman Empire, the events that caused the ...

to prepare a huge host, comprising more than 100,000 troops and 1,800 ships, to take them to the Byzantine capital,

Constantinople Constantinople (#Names of Constantinople, see other names) was a historical city located on the Bosporus that served as the capital of the Roman Empire, Roman, Byzantine Empire, Byzantine, Latin Empire, Latin, and Ottoman Empire, Ottoman empire ...

. Upon arriving outside the city's

Theodosian walls The Walls of Constantinople (; ) are a series of defensive wall, defensive stone walls that have surrounded and protected the city of Constantinople (modern Fatih district of Istanbul) since its founding as the new capital of the Roman Empire b ...

, the Arab army had some knowledge that Emperor

Leo III the Isaurian Leo III the Isaurian (; 685 – 18 June 741), also known as the Syrian, was the first List of Byzantine emperors, Byzantine emperor of the Isaurian dynasty from 717 until his death in 741. He put an end to the Twenty Years' Anarchy, a period o ...

had allied with

Bulgaria Bulgaria, officially the Republic of Bulgaria, is a country in Southeast Europe. It is situated on the eastern portion of the Balkans directly south of the Danube river and west of the Black Sea. Bulgaria is bordered by Greece and Turkey t ...

under '' Khan'' Tervel, and so, in preparation for the

Bulgarian army The Bulgarian Army (), also called Bulgarian Armed Forces, is the military of Bulgaria. The commander-in-chief is the president of Bulgaria. The Ministry of Defense is responsible for political leadership, while overall military command is in ...

, built a set of stone walls against the city and against the countryside, with the Arab camp in between. King

Pepin the Short the Short (; ; ; – 24 September 768), was King of the Franks from 751 until his death in 768. He was the first Carolingian dynasty, Carolingian to become king. Pepin was the son of the Frankish prince Charles Martel and his wife Rotrude of H ...

Francia The Kingdom of the Franks (), also known as the Frankish Kingdom, or just Francia, was the largest History of the Roman Empire, post-Roman barbarian kingdom in Western Europe. It was ruled by the Franks, Frankish Merovingian dynasty, Merovingi ...

built a number of fortified camps during his Siege of Bourbon (761) to surround the town completely. He built a complete set of lines of circumvallation and contravallation during the Siege of Bourges (762).

Modern era

The basic objectives and tactics of a military investment have remained the same in the modern era. During the

Second World War 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 ...

, there were many sieges and many investments. One of the best-known sieges of the war, which demonstrated the tactical use of investment, was the Siege of Stalingrad. During the first half of the siege, the Germans were unable to fully encircle the city and so the Soviets got men and supplies in across the

Volga River The Volga (, ) is the longest river in Europe and the longest endorheic basin river in the world. Situated in Russia, it flows through Central Russia to Southern Russia and into the Caspian Sea. The Volga has a length of , and a catchment ...

. During the second half of the battle, the complete investment of Stalingrad by the Soviets, including airspace, which prevented the construction by the Germans of an adequately large airbridge, eventually forced the starving Germans in the city to surrender. In modern times, investments and

sieges A siege () . is a military blockade of a city, or fortress, with the intent of conquering by attrition, or by well-prepared assault. Siege warfare (also called siegecrafts or poliorcetics) is a form of constant, low-intensity conflict characte ...

of cities are often combined with intensive shelling, air strikes and extensive use of

land Land, also known as dry land, ground, or earth, is the solid terrestrial surface of Earth not submerged by the ocean or another body of water. It makes up 29.2% of Earth's surface and includes all continents and islands. Earth's land sur ...

and/or

sea A sea is a large body of salt water. There are particular seas and the sea. The sea commonly refers to the ocean, the interconnected body of seawaters that spans most of Earth. Particular seas are either marginal seas, second-order section ...

mines.

References

Sources

* {{Military and war Siege tactics Ancient Roman siege warfare Military strategy

Antiquity

Middle Ages

Modern era

See also

References

Sources