Medieval Times Castles and Fortresses

There has been much confusion with the terms castle, fort, citadel, and fortress.  Although these terms have been used interchangeably, they should each have their own meaning in military architecture.  The term castle has different meanings in different parts of the world even though it is considered a private fortified residence in northwestern Europe.  The most widely recognized definition of a castle, are the fortifications of the High Middle Ages.  These castles are characterized by high walls, towers, and usually include a moat, regardless whether it was used as a private residence, military fortification, or both.

The term fort does not strictly apply to most medieval fortifications since it refers to a smaller stronghold usually occupied by only military personnel.  On the other hand, a typical medieval castle had not only a military function but also a residential and/or administrative function.  The word citadel applies to any stronghold and can be used to refer to a castle or a section of a city that has been fortified for protection.

Although the term fortress usually refers to large non-medieval fortifications, it can sometimes refer to a very large castle-like fortification or a heavily fortified city (town).  There are usually several features that are common between fortified cities and castles such as gatehouses, special roofs, crenellations, and moats.  These features were initially developed for castles and were eventually incorporated in urban fortifications as well.  The main difference between a castle and a fortress is that a fortress is usually much larger than a castle and sometimes includes a castle, especially if it is a city rather than a town.

Besides castles and fortresses, other fortified positions of the Middle Ages included observation posts, tower houses, observation posts, and coastal fortifications.  There were also fortified churches, cathedrals, and monasteries that incorporated the defensive features found in castles and fortresses.