Towton is a nondescript village in northern England, between the cities of York and Leeds. Many Britons have never heard of it: school history tends to skip the 400-or-so years between 1066 and the start of the Tudor era. Visitors have to look hard to spot the small roadside cross that marks the site of perhaps the bloodiest battle ever fought in England. Yet the clash was a turning point in the Wars of the Roses. And, almost 550 years later, the site is changing our understanding of medieval battle.