Castle designs have changed over history. This is because of changes in technology over time - as well as changes to the function and purpose of castles.
The first castles were simply 'mounds' of earth, and medieval castle designs improved on these basics - adding ditches in the Motte & Bailey design.
As technology advanced - and as attackers got more sophisticated - elaborate concentric castle designs emerged, creating a fortress almost impregnable to its enemies.
Nowadays, castles are designed for prestige, for fantasy, and to embellish a romantic view of the life of kings, queens and nobles from years gone by.
This page gives a brief overview of the history of castles, and explains why different castle designs came about. Fundamentally, these changing designs were due to the changes in the purpose and significance of castles.
The first castles, built in the Early Middle Ages (early Medieval period), were 'earthworks' - mounds of earth primarily built for defence, as enemies struggled to climb them.
During the 1000s, the Normans developed these into Motte and Bailey castle designs.
Effectively, a 'Motte' was a large mound of earth, and a 'Bailey' was the flattened area beside the mound. The 'Motte' could be surrounded with a ditch, and buildings could be placed on the bailey - made of timber or, if time permitted, stone.
The key benefit of Motte & Bailey castles was that they were very quick to build, but pretty difficult to attack. These castles were one of the primary reasons why the Normans succeeded in conquering so much of Europe.
Despite the innovations of Motte and Bailey castles, these castle designs were far from perfect.
During the 1100s and 1200s, engineers came up with a way to strengthen old Motte and Bailey castles.
To do so, they built a 'shell keep' - a thin ring of stone around the buildings on top of the castle Motte (mound). This ring of stone replaced old, sea, wooden fencing.
Of all the castle designs featured on this page, shell keeps are a relatively rare and interesting phenomenon. Only a small number still exist to today in the UK.
The Normans had pioneered building simple 'keeps', or buildings, on the top of the flattened bailey. Sometimes these were built of timber - a material that was quick, cheap, and easy to use.
However, attackers quickly learned that the simplest way to overcome such a castle was to launch flaming arrows at it, and burn the timber to the ground.
One solution to this was to build castles from stone. Although stone wasn't impregnable, it provided some protection against fire - and was much more difficult to be stormed by attackers, too.
The problem with using stone was its huge expense, the vast manpower required, and also the time - a stone castle took years to be built, rather than just weeks.
Nonetheless, as castles became more and more important (because they demonstrated the mighty strength of their owners), castle designs increasingly moved towards stone construction.
There were many problems with stone castles - not least for the fact that they were generally cold, damp, and unpleasant to live in.
In Mid-Medieval times, an architectural revolution began in Europe. This was the new, gothic style. The characteristics of gothic architecture emphasized larger and lighter windows, higher rooms, and more decorative castle designs.
These new Gothic Castles were far grander, a and much more pleasant environment to live in.
However, much later (in the 1700s), a trend for gothic fiction transformed people's ideas of these castles. Today, people tend to think of gothic castles as being eerie, deserted and haunted spots.
Despite the developments in stone castle designs, Medieval attackers were increasingly able to penetrate their defences. Common techniques included burrowing beneath the corners of towers - undermining their foundations, and encouraging the castle to collapse.
To overcome this, castle designers added thicker outer walls - and then rings of extra outer walls. The idea of the concentric castle was then born in about 1270.
A concentric castle was an extremely expensive stone castle, effectively designed to be a 'castle in a castle'. The most secure area in the centre of the castle would have been wrapped by two mighty outer stone walls.
The castles of North Wales, built by Edward I, are outstanding examples of concentric castles - and mighty to this day.
In Early Modern times - so from about the 1500s on - castles began to fade from fashion, and the very wealthy were choosing to build palaces rather than fortifications.
Part of the reason for this was the popularity of gunpowder. Stone castles - which had looked so mighty just a couple of hundred years before - were rendered puny by mighty cannons.
As defence was now less of a consideration (and diplomacy came to the fore) the rich and well-regarded in society made the choice to invest in grander palaces and gardens, more befitting of a nobler, gentler, mercantile existence.
In the 1500s in England, this trend was exemplified by Henry VIII's extravagant construction or renovation of mighty palaces, including Hampton Court near London.
In relatively modern times, some eccentric individuals - such as King Ludwig - embarked on vast castle-building sprees.
The fantastic, over-the-top castles he built - including Neuschwanstein in Germany - were to commemorate and glorify a past age, and link him to the all-powerful kings and nobles of Medieval times.
Today, people still build castles - but the purpose is most definitely for prestige and aggrandisement of personal homes, rather than for any form of defence!
Intriguingly, castles have become embedded into the public's imagination - an average person couldn't really draw a palace, but I'm sure they'd have no difficulty in sketching the towers and battlements of an archetypal castle.
This may be due to the fantasy castle designs in Disney World; due to the castles in the Super Mario video games; or perhaps due to the fairytales we're told as children. Who knows? But castles have intriguingly found a place in our popular consciousness.
© Edd Morris and exploring-castles.com, 2011-2014. All rights reserved.
Hey - I'm Edd.
I've always loved visiting amazing old castles.
I've created this site to share some of the most incredible spots in Europe.
Keep in touch on Facebook or Google+!