The Medieval period (also known as the Middle Ages) covers a span of approximately 1,000 years. A lot happened in this time that helped defined Britain as we know it, including the castles. Just about every castle in Britain comes from this time, and with them comes a legacy of legends and war. And with this in mind, the BBC have conjured up another historical programme, ‘Castles – Britain’s Fortified History‘, following closely behind the series ‘The Secrets of the Castle‘. In this three-part series, historian Sam Willis looks at their role in history, art and literature. In the first episode, which airs 4th December 9PM on BBC4, he looks at the way castles were used in invasion and against the crown.