Osprey's exploration of the complex background of the Siege of Osaka (1614-1615), as well as of the battle experiences of the opposing forces, in a compelling exploration of the conflict that led to the eventual triumph of one dynasty over another. In 1614, Osaka Castle was Japan's greatest fortification, measuring approximately 2 miles in length with double circuits of walls, 100 feet high. It was guarded by 100,000 samurai, loyal to their master: the head of the Toyotomi clan, Toyotomi Hideyori. The castle was seemingly impenetrable, however the ruling shogun of the age, Tokugawa Ieyasu, was determined to destroy this one last threat to his position as Japan's ultimate ruler.