Japan in the 16th century was made up of effectively independent kingdoms led by warrior leaders. The author examines this period of Japanese history, looking at the commanders and armies and the way in which the destruction of the elite Takeda army affected the Samurai on all sides.

When Portuguese traders took advantage of the constant violence in Japan to sell the Japanese their first firearms, one of the quickest to take advantage of this new technology was the powerful daimyo Oda Nobunaga. In 1575 the impetuous Takeda Katsuyori laid siege to Nagashino castle, a possession of Nobunaga's ally, Tokugawa Ieyasu. An army was despatched to relieve the siege, and the two sides faced each other across the Shidarahara. The Takeda samurai were brave, loyal and renowned for their cavalry charges, but Nobunaga, counting on Katsuyori's impetuosity, had 3,000 musketeers waiting behind prepared defences for their assault. The outcome of this clash of tactics and technologies was to change the face of Japanese warfare forever.