When was the first concentric castle made

As ever, historians have debated the cause at length, but one popular view has to do with siege technology. Towards the end of the 12 th century, the counterweight trebuchet emerged. This siege engine was based around a long beam attached to an axle, which was suspended above the ground using a wooden framework. The beam was held high enough that it could rotate vertically, and a sling was attached to the end to house the projectile — the trebuchet was fired by applying downward force to the opposite end of the beam, driving the end with the sling quickly upwards along a wide arc, and releasing its projectile at the top of that arc.

Early trebuchets were powered by hand, with a group of men literally pulling on ropes to swing the arm. The counterweigh trebuchet design revolutionised siege technology because it was so much more powerful, and able to throw larger projectiles much further.

This was achieved by attaching a heavy box, usually filled with stones, to the opposite end of the beam and slowly raising it until the trebuchet was ready to fire, at which point the box would be dropped, firing the weapon. These incredibly powerful counterweight trebuchets presented a great threat to the defences of motte-and-bailey and stone keep castles.

Square or rectangular stone towers were especially vulnerable, as their shape made them unable to absorb the heavy impact of a large stone missile thrown from a trebuchet. In particular, castles in the Crusader States were suffering from attacks by Islamic armies using counterweight trebuchets. Records show that Saladin was certainly using these formidable siege engines by , although it is highly likely that they were in use earlier in the 12 th century.

However, by the late 12 th century and early 13 th century, they were becoming much more widespread — counterweight trebuchets appeared in Germany in , had reached England by , and came to Iberia around Concentric castles were likely a reaction to this development in siege technology, particularly as the earliest western examples originated in the Crusader States where warfare was very common in the 12 th century. Not only did the multiple layers of thick walls offer increased protection from enemy trebuchets, but the rounded towers of concentric castles were also far more effective at absorbing and deflecting blows from enemy projectiles.

By this, we mean that the castle was made up of two or more sets of curtain walls, punctuated by round towers, arranged concentrically — that is, they are all based around the same central point. For example, most concentric castles feature two sets of walls, one of which has a wider perimeter than the other. This design, therefore, created a space between the inner and outer walls, which was sometimes known as the outer bailey, as well as featuring an inner bailey, situated inside of the inner wall circuit.

Beaumaris Castle in Wales is an excellent example of this: the outer bailey, the gap between the inner and outer curtain walls, can clearly be seen, while the large inner bailey forms the heart of the castle. The double-wall design of a concentric castle lends it great strength, as attackers would have to breach two very strong lines of defence in order to reach the centre of the castle.

Crucially, the multiple curtain walls on a concentric castle varied in height — the inner wall was taller than the outer wall, in order to afford defenders a better line of sight. Even if the outer wall was captured by an attacking force, and the outer bailey occupied, the height of the inner wall would allow defenders to rain down missiles onto enemy soldiers, effectively meaning that the attackers could not use the outer wall to their advantage.

Like any castle, a heavy siege of ballistas and trebuchets could bring down the walls which made the curtain outer wall effective against the attackers. Begin typing your search term above and press enter to search. Press ESC to cancel. Skip to content Home Popular articles What was the first concentric castle built? Popular articles. Esther Fleming September 20, Table of Contents. You can see how the thick inner wall — the stronger black line — is protected by an outer layer of defence.

The rings of walls around the heart of the castle could be any shape. Most of these castles were either square or polygonal. However, these concentric designs were almost always symmetrical, unless rocky terrain or difficult surroundings prevented such a picture-perfect layout. First came basic motte and bailey earthworks; then we had timber castles; and then stone castles. Concentric designs were an evolution of the stone castles — still built of rock, but made to be extremely defensive and hard to capture.

Building concentric castles started in the mid s, and the best examples were built in the s and early s. The first example of this design was Caerphilly Castle in Wales — which was built in about Here, for the first time, the castle was designed to make the two rings of curtain walls into two separate obstacles for attackers to overcome. Here, each wrapping wall was considered individually.

Designers began to consider each different wall to be a separate obstacle for invaders to overcome. The best examples of concentric castles were built by Edward I, in North Wales. The strength of concentric castles can be summed up in one word: defence!

This was a design that was absolutely formidable to attackers — in fact, these castles were virtually impregnable.