How abundant were castles in the Middle Ages?

That depends entirely on the culture and the year. For example, right after the Norman conquest of England, primitive motte-and-bailey castles were ubiquitous. Five hundred years later, the King was tearing down castles left and right. read more

A medieval castle was the fortified home of an important person, such as a lord or king. The medieval period, also called the Middle Ages, lasted from the 5th century CE to the end of the 15th century. read more

Castles were often built at the top of hills or where they could use some natural features of the land to help with their defense. After the Middle Ages castles weren't built as much, especially as larger artillery and cannon were designed that could easily knock down their walls. read more