You may read something here and say to yourself, “That’s not correct!”. Just keep two things in mind. First, as often is the case, much of what folks know about castles will come from television and movies …. and those TV castles will always show the late-period castles, even anachronistically, if necessary. (TV/movies are a terrible source of accurate information.) Secondly, you must keep in mind that very many changes were made to castles during the roughly 500 year Middle Ages period.
Let’s take a quick look:
10th Century: —– The earliest castle construction is known as “motte and bailey”; an earthen mound (motte) and a timber defensive wall of wooden stockade fences (bailey). Most of these castles were later rebuilt in stone. Motte comes from the French word for “mote”, and the meaning gradually moved a mound to the water-filled ditch that surrounded it. Most of these castles were later rebuilt in stone.
NOTE: The English were winning the Battle of Hastings (1066) but, snatching defeat from the jaws of victory, they foolishly believe the Normans were retreating. They chase the Normans giving up their superior higher battle position and consequently lose the Battle of Hastings. The end result? The Battle of Hastings resulted in all lands of England being claimed by the Normans who introduce Feudalism to England.
(above) Shortly after William of Normandy defeated Harold at the Battle of Hastings, a kinsman is granted estates in Kent to guard the crossing of the Medway at Tonbridge. A simple Motte and Bailey castle is raised. To dig the moat and erect the motte 50,000 tons of earth were moved. By around 1100, the wooden castle is replaced with a stone shell keep.
11th Century — marked the beginnings of stone castles. Social change was sweeping through Europe. Kings, Lords, and other Nobility were consolidating large kingdoms and gaining wealth … wealth that was needed to build stone castles, which required a substantial commitment of resources, money, and time. Next to getting wealth, the next most important thing to rich people is protecting it. So, new castles were built in stone, and many of the older wooden motte & bailey castles were rebuilt. However, the general structure and layout remained very similar and were often called “shell-keeps”.
12th Century — The massive stone keeps we normally consider to be medieval castles took shape during this century. The Greek and Turkish cultures were very proficient with stonework. Crusaders returning to Europe brought with them all kinds of newly found engineering and design, and architectural knowledge which enabled the building of large and elaborate stone fortresses throughout Europe. For example, the idea of “flanking” towers, rather than one central keep, came from the Byzantine Empire. Alnwick Castle was one of Britain’s first to utilize the new design – and these towers found fame in the 21st century, when the castle was cast as Hogwarts in the Harry Potter films.
13th Century — Castle building reaches a feverish climax. Estimates range anywhere from 500 – 700 massive and very intricate castles being built throughout Europe. Many new techniques were applied, such as, square towers gave way to round towers. The square shape was vulnerable to battering rams, had blind zones, and tunnels could be dug underneath them and then collapsed, bringing down the tower. Round towers were much stronger, less vulnerable, had no blind spots, and were much more difficult to topple.
A turning point in the history of the castle was the abandonment of Norman (aka Romanesque) architecture, and replacing it with Edwardian Concentric Castles — an inner wall surrounded by one or more outer walls providing successive lines of defense — or, a castle within a castle, with lots of buildings, walls, towers and gatehouses in one massive medieval castle complex. It is in this century whereby defensive additions were made to the castles such as the barbican, crenellations, murder holes and arrow loops in various sizes.