Ancient Age

The origins of the art of fortification go back to the times when society was established and are identified with probably the oldest of international relations: war. The possibility of facing uncontrolled crowds of armed enemies forced the towns to be surrounded with stakes, adobe walls and moats that eventually became cyclopean stone walls provided with canvases, canvases, curtains, towers, etc. The best and most important plazas were built on eminences or elevated lands later called citadels or fortresses, bastions often surrounded in part or completely by rivers, precipices or gorges so that nature contributed to isolating the enclosure with its obstacles. Those on the plains or lowlands usually had two or three rows of ditches and an equal number of defense lines. Its walls rose to 10, 12 and even more yards high, crowned with machicolations and battlements. The historian Polybius says that Syracuse (Sicily) was surrounded by moats each 45 feet wide and 22 feet deep. Jerusalem, according to the Jewish historian Flavius ​​Josephus, was surrounded by three walls except on the side of the valleys, which, due to being inaccessible terrain, only had one. In ancient times these fortifications were very common even in small cities, but urban growth, together with the invention of artillery, overwhelmed them and made them useless, so they were demolished over the centuries until today only a few remain as archaeological curiosity.

Even though the oldest towns fortified themselves with rows of stakes or posts and adobe walls, experience soon provided them with more knowledge and they improved their defenses with masonry on the main walls. The factory with sod or lawns was not unknown to them, as well as the art of supporting the lands with fascines secured and maintained with pickets, arming the top of the wall with crowns of stakes and what was later called falsabraga. They usually planted the stockade in front of or after the ditch; that is, at the foot of the counterscarp or escarpment. The walls had no embankments or sidewalks and the passage behind them was so narrow that there was barely room for a row of soldiers; The passage was interrupted from time to time with cuts on which temporary bridges were placed, which were removed when necessary. The second line of walls should not have an entrance in front of the gate of the first, but was located on one of the flanks and often on the opposite side, so that the enemy would be exposed to the safe shots of the soldiers who defended them; If there were more lines, the same system was observed.

The Romans had the custom of always camping in a defended area with post forts and moats. The besiegers also used fortifications. Depending on the circumstances, they established one or two lines of adequately defended entrenchments. The squares were surrounded with moats, blockhouses and parapets "Parapet (military)"), or modern bastions built to house cannons or machine guns in concrete reinforced with iron rods and called casemates, and they were also used against relief troops and when the site became a blockade, the lines formed solid walls garrisoned from stretch to stretch with towers or defense posts. It seems impossible that they did not consider the means of advancing the trenches to reach the edge of the ditches under cover: and yet, it was so. The attack columns marched in the open, covering a large space in which they were targets of the besieged. Other times the soldiers, equipped with sashes, came to block the ditches and went up to the siege, but always suffering considerable losses. The Romans later invented the mantlets "Mantelete (military)"), pluteos and the testudo ("turtle") formations that protected them somewhat. Finally, necessity, danger and study taught them the opportunity of zigzags or trench branches to approach the square more safely and almost without damage.

Middle Ages

Since the appearance of gunpowder on the military scene, the fortification underwent very important variations. The battlements and machicolations were replaced by bullet-proof earthen parapets and bastions, redientes, barbicans, etc. were erected in front of the plaza doors. and other earthen works supported by a covering of lime and stone, bricks, wood or ashlar stone. These fortifications delayed assaults and the opening of breaches "Brecha (military)"). With the name of outskirts, fortifications were established that were considered as parts of the front or the enclosure. The same counterscarp surrounded the body of the plaza and the exterior works, developing around the fortress a parapet in the form of an esplanade glacis and between this and the counterscarp there was a free and hidden space that was called the covered road: then came the notable works, the cuts, wolf pits, felling of trees, entrenchments and counterguard lines, a kind of sap through which the besieged approached the enemy, falling on the flanks of their trenches.

Modern Age

In 1527 Juan Michelli") fortified Verona with bastions; in 1543 Hesdios") and Landrecies built regular squares and bastions. Villay") used the counterattack line in the defense of Rouen (1592). The corridor or covered path known for a long time received notable improvements: the outskirts, the exterior and outstanding works prolonged the sieges during the civil wars of the Netherlands. In 1618 Stevin wrote the way of fortifying by means of locks. The besieger, therefore, to enter a square had to reach the crest of the glacis, open the escarpment, pass the ditch, attack or establish itself in the breach under the triple effect of exits, fires and countermines. After this multitude of works were known, the fortification that in ancient times had a single and uniform appearance, was susceptible to receiving a multitude of figures.

Vauban finally appeared and his talent developed more means of attacking and defending the squares. It accommodated using the topography of the terrain for siege tactics; He perfected the use of trench branches, invented the sapa, the parade grounds, the redoubts, the parallels, the crowning of the covered road and other procedures. From then on, the superiority of the attacker over the besieged was already overwhelming: the besieger was always able to present a larger front than the attacked, using the same machines and identical means of causing damage as the besieged. Through the zigzags it reached with branches of trenches to the edge of the counterscarp where the artillery was placed.

Coehorn"), a Dutch engineer, was a worthy emulator of him and was later followed by other military engineers such as Louis de Cormontaigne, Duvignau, D'Arzón, Boussmard, François de Chasseloup-Laubat") and other famous engineers. Baudoin, Bonnet, André-Joseph Lafitte-Clavé"), in their memoirs on borders, have sought the principles of that art in which Vauban combined fortification with topography and the art of war.

Contemporary Age

The contributions of the fortification in the century consisted of multiplying the flanks. In the general relief, Vauban's profile was preserved as the only one that combined economy and simplicity with the advantage of only opposing enemy fire with land, parapets against projectiles and, on the walls, the circulation and maneuvers of artillery and troops. In the layout, all the works were made larger in order to be more favorable to these maneuvers, to be able to place the crossbars and armor during the siege and, due to their very spaciousness, to make the effects of the projectiles less dangerous. Under the name desenfilada, the art with which Vauban, placing his works on planes that passed over all the heights that could dominate them, protected his fortifications from direct fire was reduced to general rules and the admirable method of raising the plane of an elevated terrain by horizontal curves allowed him to be able to draw a fortification both inside a cabinet and on the same terrain. In the layout of the advanced and exterior works, the objective was to simultaneously protect the main lines of the enclosure from ricochet shots, give the works all possible exit, without ceasing to be linked to the others that protect them, leave unassailable spaces between them, make successive attacks and above all favor the exits of the garrison and facilitate the recovery of the parts already taken. Trenches and mobile removable fortifications using sandbags (gabions "Gavion (military)") began to be used against howitzers. Finally, the countermines were attached to the fortification, concentrating them at the points at which the besieger loses part of the advantages that the suppression of countermines and the violence of their stoves give him.[4]​.

Ancient Age

The origins of the art of fortification go back to the times when society was established and are identified with probably the oldest of international relations: war. The possibility of facing uncontrolled crowds of armed enemies forced the towns to be surrounded with stakes, adobe walls and moats that eventually became cyclopean stone walls provided with canvases, canvases, curtains, towers, etc. The best and most important plazas were built on eminences or elevated lands later called citadels or fortresses, bastions often surrounded in part or completely by rivers, precipices or gorges so that nature contributed to isolating the enclosure with its obstacles. Those on the plains or lowlands usually had two or three rows of ditches and an equal number of defense lines. Its walls rose to 10, 12 and even more yards high, crowned with machicolations and battlements. The historian Polybius says that Syracuse (Sicily) was surrounded by moats each 45 feet wide and 22 feet deep. Jerusalem, according to the Jewish historian Flavius ​​Josephus, was surrounded by three walls except on the side of the valleys, which, due to being inaccessible terrain, only had one. In ancient times these fortifications were very common even in small cities, but urban growth, together with the invention of artillery, overwhelmed them and made them useless, so they were demolished over the centuries until today only a few remain as archaeological curiosity.

Even though the oldest towns fortified themselves with rows of stakes or posts and adobe walls, experience soon provided them with more knowledge and they improved their defenses with masonry on the main walls. The factory with sod or lawns was not unknown to them, as well as the art of supporting the lands with fascines secured and maintained with pickets, arming the top of the wall with crowns of stakes and what was later called falsabraga. They usually planted the stockade in front of or after the ditch; that is, at the foot of the counterscarp or escarpment. The walls had no embankments or sidewalks and the passage behind them was so narrow that there was barely room for a row of soldiers; The passage was interrupted from time to time with cuts on which temporary bridges were placed, which were removed when necessary. The second line of walls should not have an entrance in front of the gate of the first, but was located on one of the flanks and often on the opposite side, so that the enemy would be exposed to the safe shots of the soldiers who defended them; If there were more lines, the same system was observed.

The Romans had the custom of always camping in a defended area with post forts and moats. The besiegers also used fortifications. Depending on the circumstances, they established one or two lines of adequately defended entrenchments. The squares were surrounded with moats, blockhouses and parapets "Parapet (military)"), or modern bastions built to house cannons or machine guns in concrete reinforced with iron rods and called casemates, and they were also used against relief troops and when the site became a blockade, the lines formed solid walls garrisoned from stretch to stretch with towers or defense posts. It seems impossible that they did not consider the means of advancing the trenches to reach the edge of the ditches under cover: and yet, it was so. The attack columns marched in the open, covering a large space in which they were targets of the besieged. Other times the soldiers, equipped with sashes, came to block the ditches and went up to the siege, but always suffering considerable losses. The Romans later invented the mantlets "Mantelete (military)"), pluteos and the testudo ("turtle") formations that protected them somewhat. Finally, necessity, danger and study taught them the opportunity of zigzags or trench branches to approach the square more safely and almost without damage.

Middle Ages

Since the appearance of gunpowder on the military scene, the fortification underwent very important variations. The battlements and machicolations were replaced by bullet-proof earthen parapets and bastions, redientes, barbicans, etc. were erected in front of the plaza doors. and other earthen works supported by a covering of lime and stone, bricks, wood or ashlar stone. These fortifications delayed assaults and the opening of breaches "Brecha (military)"). With the name of outskirts, fortifications were established that were considered as parts of the front or the enclosure. The same counterscarp surrounded the body of the plaza and the exterior works, developing around the fortress a parapet in the form of an esplanade glacis and between this and the counterscarp there was a free and hidden space that was called the covered road: then came the notable works, the cuts, wolf pits, felling of trees, entrenchments and counterguard lines, a kind of sap through which the besieged approached the enemy, falling on the flanks of their trenches.

Modern Age

In 1527 Juan Michelli") fortified Verona with bastions; in 1543 Hesdios") and Landrecies built regular squares and bastions. Villay") used the counterattack line in the defense of Rouen (1592). The corridor or covered path known for a long time received notable improvements: the outskirts, the exterior and outstanding works prolonged the sieges during the civil wars of the Netherlands. In 1618 Stevin wrote the way of fortifying by means of locks. The besieger, therefore, to enter a square had to reach the crest of the glacis, open the escarpment, pass the ditch, attack or establish itself in the breach under the triple effect of exits, fires and countermines. After this multitude of works were known, the fortification that in ancient times had a single and uniform appearance, was susceptible to receiving a multitude of figures.

Vauban finally appeared and his talent developed more means of attacking and defending the squares. It accommodated using the topography of the terrain for siege tactics; He perfected the use of trench branches, invented the sapa, the parade grounds, the redoubts, the parallels, the crowning of the covered road and other procedures. From then on, the superiority of the attacker over the besieged was already overwhelming: the besieger was always able to present a larger front than the attacked, using the same machines and identical means of causing damage as the besieged. Through the zigzags it reached with branches of trenches to the edge of the counterscarp where the artillery was placed.

Coehorn"), a Dutch engineer, was a worthy emulator of him and was later followed by other military engineers such as Louis de Cormontaigne, Duvignau, D'Arzón, Boussmard, François de Chasseloup-Laubat") and other famous engineers. Baudoin, Bonnet, André-Joseph Lafitte-Clavé"), in their memoirs on borders, have sought the principles of that art in which Vauban combined fortification with topography and the art of war.

Contemporary Age

The contributions of the fortification in the century consisted of multiplying the flanks. In the general relief, Vauban's profile was preserved as the only one that combined economy and simplicity with the advantage of only opposing enemy fire with land, parapets against projectiles and, on the walls, the circulation and maneuvers of artillery and troops. In the layout, all the works were made larger in order to be more favorable to these maneuvers, to be able to place the crossbars and armor during the siege and, due to their very spaciousness, to make the effects of the projectiles less dangerous. Under the name desenfilada, the art with which Vauban, placing his works on planes that passed over all the heights that could dominate them, protected his fortifications from direct fire was reduced to general rules and the admirable method of raising the plane of an elevated terrain by horizontal curves allowed him to be able to draw a fortification both inside a cabinet and on the same terrain. In the layout of the advanced and exterior works, the objective was to simultaneously protect the main lines of the enclosure from ricochet shots, give the works all possible exit, without ceasing to be linked to the others that protect them, leave unassailable spaces between them, make successive attacks and above all favor the exits of the garrison and facilitate the recovery of the parts already taken. Trenches and mobile removable fortifications using sandbags (gabions "Gavion (military)") began to be used against howitzers. Finally, the countermines were attached to the fortification, concentrating them at the points at which the besieger loses part of the advantages that the suppression of countermines and the violence of their stoves give him.[4]​.