Medieval fortification

During this millennium, fortifications changed warfare, and in turn were modified to suit new tactics, weapons and siege techniques.

The Ayyubids between 1196 and 1218 built towers mounted with massive trebuchets, which hypothetically would use their height advantage to take out opposing siege engines.

This is because their missiles sometimes lacked the force to dismantle enemy siege engines and their immobility confined them to the top of a city's towers were they could easily be taken out by enemy catapults, including offensive ballistas which were usually employed for the very reason of dismantling defenses on the top of towers and keeping defenders off of a wall's battlements.

[2] However slow to load, cannons proved to be devastating weapons that could level a city's walls or destroy siege engines with only a single projectile.

An external pomoerium, stripped of bushes and building, gave defenders a clear view of what was happening outside and an unobstructed field of shot.

An internal pomoerium gave ready access to the rear of the curtain wall to facilitate movement of the garrison to a point of need.

Also by that time, the medieval walls were no longer secure against a serious threat from an army, as they were not designed to be strong enough to resist cannon fire.

Very elaborate and complex schemes for town defenses were developed in the Netherlands and France, but these belong mainly to the post-medieval periods.

By 1600, the medieval wall is likely to have been seen more as a platform for displaying hangings and the pomery as a gathering ground for spectators, or as a source of building stone and a site for its use, respectively.

The concept of rivers or harbors coming directly up to the walls of fortifications was especially used by the English as they constructed castles throughout Wales.

Religion was a central part of the lives of medieval soldiers, and churches, chapels, monasteries, and other buildings of religious function were often included within the walls of any fortification, be it temporary or permanent.

The string of Welsh castles Edward I of England had built were an exception in that he focused much of the resources of his kingdom on their speedy construction.

In addition to paid workers, forced levies of labourers put thousands of men on each site and shortened construction to a few years.

Some also featured machicolations (from the French machicoulis, approximately "neck-crusher") which consisted of openings between a wall and a parapet, formed by corbelling out the latter, allowing defenders to throw stones, boiling water, and so forth, upon assailants below.

Soldiers would be positioned atop the second wall and armed with any variety of weapons, ranging from bows to crossbows to simple rocks.

To position a castle on a small island was very favorable from a defensive point of view, although it made deliveries of supplies and building materials more cumbersome and expensive.

These were steps that had different rise height or tread depth from the rest and would cause anyone running up the stairs to stumble or fall, so slowing down the attackers' progress.

From the mid-15th century onwards, the power of cannons grew and medieval walls became obsolete as they were too thin to offer any realistic protection against prolonged bombardment.

[6] As a consequence of this, medieval walls were often upgraded with the addition of artillery platforms or bastions, and battlements were replaced by thick parapets with embrasures.

[7] 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 for example in Prague and Florence, Italy).