The earliest castles are thought to be build in the 9th and 10th centuries. Feudal Lords used to build these castles for the defense and base camp for soldiers. These castles were initially made up of earth and timber. Castles in Europe emerged from the very first wooden fortress made to lodge a battalion to magnificent stone construction capable to hold up a small army for extended period.
Castles were infact the equipped house of the feudal aristocrat or ruler. During the wars of the late Middle Ages the castles became almost ubiquitous in Western Europe. The initial structure of the castle was made up of a plain wooden construction encircled by a trench. Incase the domains were flat the lords orders to construct an artificial mound, or motte. As the time passed and the medieval craft work became famous chain of walls called as palisades lift up all around the motte and they name the open area inside these walls the bailey. During 11th century motte-and-bailey form of the castles were quite common. Now these outer walls were made thicker and on top of them were open battlemented parapets.
The next tread in the construction of these castles was the addition of towering masonry keep called as donjon inside the bailey done by the Normans. These donjons were usually 40 to 50 ft high and consist of small windows and thick walls. We will find the example of such Norman donjons in the white tower inside The Tower of London. the crude ditches were replaced by wide and deep moats. They were often dry moats and were crossed by drawbridges that may well be raised from inside the castle. At the castle end of the drawbridge was a breach in the wall which contain a portcullis which is a thick iron-plated wooden gate that can be elevated to clear the doorway. Inside the Norman donjons were personal residential area, a water well and all the things which were required to sustain the residents of the castle throughout a long siege.