To keep the Welsh out!
because after Edward III defeated Llewellyn of wales he built lots of castles in wales
Because Wales was considered an outcast to the English so they would never go looking for the King of England there.
Wales itself is a single country so there are no countries in Wales.
so the army
Because he felt like it. only joking he wanted to be able to see what was going on around the country and he wanted to show people that he was powerful enough to defeat them if they tried to attack him.
The Castles in 1066 were used for:defence, homes,and they were used mainly by King William Duke Of Normandy to take over the country and he mostly built them on high ground to see a 10 mile radius over the land. so mainley the castles were used to take over england by force and if anybody stood in williams way; bascally they died. there was undreds of castles spread over the country but they were mainly by the borders os scotland and wales so that is anybody was to try and invade for either wales or scotland the castles were the first things they would have faced. but they were also placed on the edges of the countre, the seasides to add protection from being invaded by sea.
Because the number of castles is so great it is recommended to see the link below.
Because there were many different kinds of wealthy people.
William the conqueror use castles to control England because the castles shown power and defence. After the Harrying of the North, no one dared to attack the castles because they were to afraid. Also, the Churches were the biggest buildings so when William built the castles that were bigger than churches the people were amazed!
*
it means the top of a place so like north wales on the very top they have called it Llandudno.
It is approximately 5,000, although it varies above or below this slightly depending upon how many people move in and how many move out every 10 years or so.