Military engineering is loosely defined as the art, science, and practice of designing and building military works and maintaining lines of military transport and military communications. Military engineers are also responsible for logistics behind military tactics. Modern military engineering differs from civil engineering. In the 20th and 21st centuries, military engineering also includes CBRN defense and other engineering disciplines such as mechanical and electrical engineering techniques.
A defensive wall is a fortification usually used to protect a city, town or other settlement from potential aggressors. The walls can range from simple palisades or earthworks to extensive military fortifications with towers, bastions and gates for access to the city. From ancient to modern times, they were used to enclose settlements. Generally, these are referred to as city walls or town walls, although there were also walls, such as the Great Wall of China, Walls of Benin, Hadrian's Wall, Anastasian Wall, and the Atlantic Wall, which extended far beyond the borders of a city and were used to enclose regions or mark territorial boundaries.
A hillfort is a type of earthwork used as a fortified refuge or defended settlement, located to exploit a rise in elevation for defensive advantage. They are typically European and of the Bronze Age or Iron Age. Some were used in the post-Roman period. The fortification usually follows the contours of a hill and consists of one or more lines of earthworks, with stockades or defensive walls, and external ditches.
Medieval fortification refers to medieval military methods that cover the development of fortification construction and use in Europe, roughly from the fall of the Western Roman Empire to the Renaissance. During this millennium, fortifications changed warfare, and in turn were modified to suit new tactics, weapons and siege techniques. Watchtower Towers of medieval castles were usually made of stone, wood or a combination of both (with a stone base supporting a wooden loft).
A bastion fort or trace italienne (a phrase derived from non-standard French, literally meaning 'Italian outline') is a fortification in a style that evolved during the early modern period of gunpowder when the cannon came to dominate the battlefield. It was first seen in the mid-fifteenth century in Italy. Some types, especially when combined with ravelins and other outworks, resembled the related star fort of the same era. The design of the fort is normally a polygon with bastions at the corners of the walls.
A castle is a type of fortified structure built during the Middle Ages predominantly by the nobility or royalty and by military orders. Scholars usually consider a castle to be the private fortified residence of a lord or noble. This is distinct from a mansion, palace and villa, whose main purpose was exclusively for pleasance and are not primarily fortresses but may be fortified. Use of the term has varied over time and, sometimes, has also been applied to structures such as hill forts and 19th- and 20th-century homes built to resemble castles.
A battering ram is a siege engine that originated in ancient times and was designed to break open the masonry walls of fortifications or splinter their wooden gates. In its simplest form, a battering ram is just a large, heavy log carried by several people and propelled with force against an obstacle; the ram would be sufficient to damage the target if the log were massive enough and/or it were moved quickly enough (that is, if it had enough momentum). Later rams encased the log in an arrow-proof, fire-resistant canopy mounted on wheels.
A siege is a military blockade of a city, or fortress, with the intent of conquering by attrition, or by well-prepared assault. This derives from sedere. Siege warfare is a form of constant, low-intensity conflict characterized by one party holding a strong, static, defensive position. Consequently, an opportunity for negotiation between combatants is common, as proximity and fluctuating advantage can encourage diplomacy. A siege is conducted (by the attacking force) by siegecraft, or poliorcetics.
A cannon is a large-caliber gun classified as a type of artillery, which usually launches a projectile using explosive chemical propellant. Gunpowder ("black powder") was the primary propellant before the invention of smokeless powder during the late 19th century. Cannons vary in gauge, effective range, mobility, rate of fire, angle of fire and firepower; different forms of cannon combine and balance these attributes in varying degrees, depending on their intended use on the battlefield.
Suomenlinna (ˈsuo̯menˌlinːɑ; until 1918 Viapori, ˈviaˌpori), or Sveaborg (ˈsvɛːɑˈborj), is an inhabited sea fortress composed of eight islands, of which six have been fortified; it is about 4 km southeast of the city center of Helsinki, the capital of Finland. Suomenlinna is popular with tourists and locals, who enjoy it as a picturesque picnic site. Originally named Sveaborg (Castle of the Swedes), or Viapori as referred to by Finnish-speaking Finns, it was renamed in Finnish to Suomenlinna (Castle of Finland) in 1918 for patriotic and nationalistic reasons, though it is still known by its original name in Sweden and by Swedish-speaking Finns.