Many of the Gothic architectural designs used during the Medieval had military purposes and served to improve building strength and efficiencies, in addition to bringing elaborate creativity and designs. Aside from its influence on general building design, Gothic architecture also played a large role in the development of gates and bridges. Architects of the time attached great importance to the development and design of these structures, just as they understood the importance of tower and vault innovation.
Gates served as an entrance to castles and other fortresses; this meant that planning for this object had to combine safety, strength and of course, aesthetics. Gate construction was framed around the need to repulse any attackers and to avert potential invasion. Successful construction of a gate meant that its strength and appearance would be deter possible invaders. In theory this meant that fortresses and castles would only typically be taken by ruse, treason or surprise rather than by siege because of a gate’s success.
During the 12th and 13th century great emphasis was placed on fortifying gates to increase their strength and durability. Typically, gates were approached over a bridge by raising a movable portion. Often, the entrance was barred to add protection. The narrow gateway passage was defended by two projecting towers, which were connected by a stone curtain. The entire structure together formed a fortified gate-house, known as a châtelet.
The passage was further defended by a single or double portcullis, cased with iron, and often these structures were spiked at the bottom. Passages were also defend by machicolationsor holes in the roof, through which the garrison could hurl down weapons on the heads of their enemies. A present day example of this would be the castle-gate of Carsaaonne, built approximately 1120 in France.
In the 13th century military architects provided increased protection against surprise attacks by including more defensive outworks. Constructive methods were used to increase the strength and durability of fortified gates; as architectural design progressed, military architecture also progressed.