In 1614-15 Osaka Castle was Japan's greatest fortification, measuring approximately 2 miles in length with walls 100 feet high. It was guarded by 100,000 samurai, determined to defend the last of the once-powerful Toyotomi clan. The castle was seemingly impenetrable; however, Tokugawa Ieyasu, the founder of the ruling dynasty, was determined to destroy this remaining threat to the Tokuwaga ruling dynasty. This book explores the bitter struggle of the Summer and Winter campaigns, which eventually saw the last great clash of the samurai and defined the balance of power in Japan for years to come.