����ý

Stone castles had a number of advantages over wooden motte and bailey structures:

• They could be built inside the walls of the motte and bailey castle, this meant that the castle was still operational whilst it was being rebuilt.
• Unlike a wooden castle the new stone keeps did not rot or go up in flames.
• Stone castles were very expensive to build but they demonstrated the wealth and power of the lord that built it.

The first stone tower was built in 1070 by William I, and is known today as the Tower of London. Between 1070 and 1087 an additional 85 stone castles were built across England.

The most visible part of a stone castle was the central stone tower. This was built at the highest point of the fortification. This had a number of advantages:

• The height of these towers meant they could be seen by people from miles away, this demonstrated the power of Normans. It also gave look outs and archers excellent defensive positions, these castles were rarely attacked without warning and they were an excellent base to attack from.
• The lord could live in much greater luxury in a stone keep. Bigger fires could be kept and rain was no longer a major problem.
• The keep was the first part of the castle built and was expected to be the last part to fall to the enemy. A lord and many of his soldiers could survive a siege of months inside the keep whilst waiting for reinforcements.

Although they seemed impenetrable at first, attackers quickly realized the weaknesses of many stone keep castles.

• They were expensive to build and to maintain and so only the wealthiest lords could afford to build very secure stone castles.
• Stone castles were built on a square or rectangular plan. Attackers had to simply find a way of tunnelling underneath one of the corners to bring down a whole section of the castle.
• Siege weapons like the trebuchet could fire heavy rocks, if these missiles hit a flat surface there would be major damage to the castle.