In this three-part series for BBC Four, intrepid historian Dr. Sam Willis reveals a remarkable story of invasion in Britain, spanning thousands of years.From the time that continuous settlement began in Britain over 10,000 years ago, to Iron Age hillforts and Viking ships, Sam Willis explores the many invasions of Britain. He unearths hidden stories to build a vivid picture of both successful and unsuccessful invasions and examines how they have shaped our psyche - including fear of invasion.Some invasions are bloody, some bloodless. Some were by invitation, some absurd and doomed. From Barbary pirates and brutal border raids to the air attacks of the 20th century, these invasions have shaped modern Britain and made us the people we are today.