The success of George R.R. Martin's A Song of Ice and Fire novels and HBO's Game of Thrones series underscores the perennial popularity of medieval history-or rather medievalism, the idea of the Middle Ages. Medievalist movies, books and video games are lucrative property in the multi-billion-dollar entertainment industry, and Renaissance fairs, reenactment groups and historical martial arts clubs have become prominent in pop culture. Yet actual medieval history-especially medieval military history-remains a niche subject of scholarship. This book, written by an historian and medieval martial arts expert, explains how Martin's fantasy world reflects real history.