How did castles change over time? (give multiple examples, why good and why bad)

Castles were primarily built to defend and protect, but over time comfortable homes evolved within the fortified walls. The first castle of stone consisted of rectangular towers surrounded by high stone walls.

Explanation:

From 1066 - 1500 over 1,500 castles were built in England and Wales. Over this time the way they were built changed a great deal. Most of the reasons castles changed were because attackers found new ways of breaking into them. Castle defences needed to change to keep these attackers out.