The Normans built around 500 castles of varies types and size throughout England and Wales after the invasion of England in 1066. About 90 are still standing, many intact and still occupied and many in a state of ruin. The link below has more good information about Norman Castles.
In the year of 1066 during the invasions of Britain Scotland and Wales castles were built in every realm to defend the city or town there these realms are now called counties of england scotland and wales such as essex wessex sussex etc
There were no castles in the British Isles until the arrival of the Normans from France in 1066. They brough with them the knowledge and skills of castle building. The Normans built around 500 castles in England and Wales. About 90 are still standing either intact or as ruins.
In 1066 castles were attacked by weapons such as swords and bow and arrows. Whilst your here... William the Conqueror was king at the time. Motte and Bailey castles were the first castles. Thank you for reading, I hoped this helped! -Izzy.G.G