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Why Were Medieval Castles Built?

You might notice a lot of castles when travelling through Europe, and probably asked yourself why the Medieval castles were built?

Why medieval castles were built?
Image by Cari R. from Pixabay

The Medieval Castles were built in the Middle Ages as a home of the kings and nobles, to show power and wealth. Also, castles were a strategic place of retreat and defence against unwanted intruders and during local battles or between countries.

There is much more to find out about the history, evolution, and features of Medieval Castles.

History of Medieval Castles 

People built the castles for many purposes; of course, the principal one remains the military but also represents the power, wealth, administrative and many domestic attributions.

Our ancestors built the first-ever fortification much earlier than the Middle Ages originated in Indus Valley, Egypt and China where massive walls protected the settlement.

In Europe, the number of castles started to rise significantly in the 9th-10th century when in the result of Magyars, Muslims and Viking’s invasion where Kings, nobles and locals needed defence.

The most common location is the high rise of the hill, where the builders took into consideration the critical factors like their own water and food supply, also the number of people it can hold for an extended period in case of a siege.

First-ever castles were built from wooden materials gradually evolving over the years into stone made thick walls.

Building a castle back in the day was a costly and time-consuming campaign that required many years and loads of skilled people to finish.

In many cases, the building of the castle could not even start without the king’s permission.

Towards the end of the Middle Ages, the military importance of the castle started to drop as a result of weapons evolution. 

With new, more powerful artillery cannons, even the mightiest castles could not stand longer than a few hours of the attack.

Types of castles

If you are a frequent traveller or love historical movies, you’ve probably noticed not all the castles are the same;

There are different types of castles;

  • Motte and Bailey Castle 
  • The Rectangular Keep Castle 
  • The Shell Keep 13 century Castle 
  • The Concentric Castle

Motte and Bailey Castle

This type of castle was predominant at the beginning of the castle age.

The Motte is a small hill where the jeep is located and the Bailey it’s a courtyard surrounded by a deep, circular ditch, the soil after the digging has been used for raising the hill.

The Rectangular Keep Castle 

Also known as donjon or dungeon are most frequently seen and still-standing nowadays.

They were built out of stones, as tall as possible and with useful improvements on the Motte and Bailey.

The Shell Keep 13th Century

After many years of exploitation, the Master masons (Architects In Middle Ages ) realised the wood structure was weak for an extended period.

They improved the Motte and Bailey into the stone structure, with a circular or semicircular shape of the whole site.

The Concentric Castle

Concentric Castle was a more sophisticated and strategically built castle during the 13th and 14th centuries.

Combination of shell keep and rectangular keep with more lines of defence; including moats, towers and turrets.

Features the Medieval Castle.

As you admire the castle today it doesn’t seem like a sophisticated building, but back in the day even the smaller ones had all the defensive features needed against the attack;

  • Keep 
  • Bailey 
  • Curtain wall & towers 
  • Moat
  • Barbican
  • Fortified gatehouse 

Keep of Medieval Castle 

Is a fortified structure inside of the castle, usually the main building made out of a stone with thick walls used as a last resort of defence.

Example of a Keep of the castle on Motte hill
Example of Keep, Picture by Mario Sanchez Prada on

Emerged from Normandy and Anjou in the 10th century first Keeps were made from timber, and formed the vital part of Motte and Bailey.

The design of the keep later spread to Italy,

Sicily, England and Wales and in 1170 in Ireland.

These Rectangular or circular Norman keeps held considerable political and military importance and could take rulers to build them up to a decade.

During the 12th century, you could see the new designs coming up in the construction of castles.

In the 14th century was a rebirth of building keeps, in a new fashion with taller roofs and much bigger halls as a new trend among the wealthy nobles.

Later in the 15th century, it could not resist the might of the quickly improving artillery, and gradually, the castles came out of the use or have been destroyed during the civil wars.


Bailey is an enclosed courtyard surrounded by a curtain wall, often overlooked by the Motte.

An example of the bailey shown in this picture

Example of the bailey, Picture by Vince on

A castle could have multiple Baileys depending on the number of vassals and technology, and the strategy of defence.

The Bailey also hosted several buildings like; shops, workshops, accommodation for the soldiers and on some bigger castles, even a church.

Curtain Wall & Towers 

A curtain wall & tower is a thick defensive structure made out of stone that usually surrounds the Bailey of the Castle or a small medieval town.

Example of Curtain Wall and Towers, Picture by Egor Dubrovsky on

There is much evidence of curtain walls being built in the early 5th century across Europe during the Roman Empire.

Depending on the castles the walls varied in thickness averages around 2-3m.

The builders raised the curtain wall at a considerable height and with a moat in front, so it made it difficult for an assault.

Through the years the towers have been added to improve the angle the archers can shoot, and made it harder for an enemy to climb on the walls.


Moat is a deep, broad ditch filled with water or dry, surrounding the castle at the bottom of the curtain wall used as the primary line of defence.

Example of the Moat of a castle on Bodiam Castle
Example of the Moat of a castle, Picture by thecrypt on

Through the years as the castles developed and became more sophisticated, the moats enlarged too and a more significant size moat.

Moats were deep enough so none of the soldiers, siege tower or other war equipment could get any closer to the curtain wall.

Curious about moats? There is a whole article about the history and development of castle moats in our blog section.  


Barbican is a fortified outpost or gateway, such as an outer defence structure situated at the gate of a castle or a medieval city. 

With Barbican built outside the castle and connected with a protected bridge called “neck,” the archers could stop slow down a direct attack on the gates or weak points of the castle.

Whit the improvement of the siege tactics and artillery the Barbicans lost their importance in the 15th century. However, there are many barbicans built during the 16th century.

Fortified gatehouse

It’s a fortified structure designed to protect the entrance of the castle or medieval town, which was the weakest point during the siege.

Example of Fortified Gate House of  castle
Example of Fortified Gate House of castle Picture by Hugh Llewelyn  on

Out of all the features of a castle, the gatehouse probably suffered the most modifications during the Middle Ages.

Being vital access for the owners and the main target for the enemy, the architects transformed them into a deadly trap for many brave soldiers.

Most impregnable gatehouse has multiple stages of defence;

  • barbicans(which developed into twin towers), 
  • drawbridges
  • wooden thick doors.
  • portcullis (sliding metal doors from the ceiling )
  • murder holes ( high above, small in size openings to throw stones and deadly liquids.

In a few words, a defence feature made a hard time for any army that tried to pretend for the castle throne.


Living in the Middle Age era every kingdom trying to acquire new land, therefore building a castle was crucial. That’s why there are so many castles left behind in our history.

We hope you have enjoyed the article, thanks for stopping by and don’t forget to check out our blog section for many more interesting articles.

Which country has the most castles?

The country with the most castles in the world is Germany. It is estimated that there are about 25,000 castles in this country! However, the exact figure is still yet to be disclosed by the European Castle Institute.

What is the Oldest Standing Castle in the World?

Formerly the oldest standing castle was in Aleppo, northern Syria, built around 3000BC.

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