After 1066 the Normans built castles all over England and Wales. Edward I had a hand in creating at least 17 castles in Wales. Who planned them? Let's find out.

An architect plans a building. Master James of St George was the architect of Edward I's Welsh castles. Beaumaris, Caernarfon, Conwy and Harlech were named a UNESCO World Heritage Site in 1986.

Many early castles were made of wood. Motte and bailey castles could be built quickly, from earth and timber found close at hand. From the 1100s some owners rebuilt wooden castles in stone, with a stone keep. Sites such as cliffs, marshes and high ground gave a castle natural protection.

Some of the defences were clever. A concentric castle had two rings of walls, one inside the other. The inner wall was higher. So archers could shoot over the heads of soldiers on the outer wall. Towers stuck out from the wall. They gave defenders a better view and a wider field of fire.

New walled towns were built next to castles such as Caernarfon and Conwy. Castles were places where people lived and worked, not only forts.

Over time, life inside a castle changed. As the Middle Ages went on, castles became more comfortable. Some were used for courts and offices. Then gunpowder and cannon came. Castle defences could be damaged more easily, so castles mattered less.

Words to know

• architect: building planner
• concentric: rings inside rings
• UNESCO: world heritage group