Medieval fortification is the military aspect of Medieval technology that covers the development of fortification construction and use in Europe roughly from the fall of the Roman Empire to the Renaissance. During this millennium, fortifications changed warfare, and in turn were modified to suit new tactics, weapons and siege techniques.

Fortification types

Castles

Towers

City walls

Harbours

Churches

Monasteries

Mottes, Baileys

Motte and bailey was the prevalent form of castle during 11th and 12th centuries. A courtyard (called bailey) was protected by a ditch and a palisade (strong timber fence). Often there was an entrance, protected by a lifting bridge, a drawbridge or a timber gate tower. Inside the bailey were stables, workshops, a well and a chapel.

Motte was the final refuge in these type of castle. It was a raised earth mound. Its height varied between 5m (15 ft) to 10m (30 ft). There was a tower on top of the motte. In most cases, the tower was made of timber, though some were also made of stones. Stone towers were found in natural mounds, as artificial ones were not strong enough to support stone towers. Larger mottes had towers with many rooms, including the great hall. Smaller ones had only an watch tower.

Construction

Materials

Costs

Manpower

Structure and Elements

Walls

• Height
• Width
• Crenelation and parapets
  • Machicolation: Machicolations (from the French word machicoulis, implying a meaning of something like "neck-crusher") consisted of openings between a wall and a parapet, formed by corbelling out the latter, so that the defenders might throw down stones, melted lead, and so forth, upon assailants below.
• Inner walls and gates

Gates

• Importance of gates
• Defences

Towers

Moats

A moat was a common addition to medieval fortifications, and the principal purpose (just as in antiquity) to make the walls harder to assail and increasing their effective height. In many instances, natural waterpaths were used as moats, and often extended through ditches to surround as much of the fortification as possible. To position a castle on a small island was very favourable from a defensive point of view, although it made deliveries of supplies and building materials more cumbersome and expensive.

To facilitate transportation but still maintaining the advantage of the construction, a drawbridge was often constructed as a part of the bridge spanning the moat.

Keeps and citadels

Stairs

At this time, stairs were generally winding, and constructed as to give a defensive edge to a defender. A general principle was the defender was often positioned higher that an assailant who presumably entered on the ground floor. As most people are right handed, and the defender higher up, the stair was constructed right turning in the direction of ascent, forcing the assailant to fight with his sword hand close to the central pillar of the stair, thus limiting his ability to maneuver and attack.

Doors

City planning

Dismantling fortifications

As the power of cannons grew during the 16th and 17th century, medieval walls became obsolete as they were too thin to offer any realistic protection against prolonged bombardment. As a consequence of this, many walls from medieval times were torn down and the stone (still valuable as construction material) reused in more modern bulwarks and bastions. The resulting space is often seen in old city centers of Europe even to this day, as broader streets often outline where the old wall once stood (evident is for example Prague and Florence, Italy).

Defensive Obstacles

Just as modern military engineers enhance field fortifications with obstacles such as barbed wire, Mediaeval engineers had a number of obstacle types at their disposal, including:

• abatis
• caltrops
• cheval de frise
• trou de loup

See also: Medieval warfare, Medieval naval warfare , siege weaponry , Abatis

Factors influencing fortification construction:'

Siegecraft:

• The Trebuchet
• Gunpowder
• The Cannon