Kawanakajima is unique in history. In the space of 12 years, between 1553 and 1564, this valley deep in the mountains of central Japan witnessed no fewer than five battles between two of Japan's greatest warlords. Takeda Shingen and Uesugi Kenshin were both descended from great families and were highly skilled tacticians. Both had taken the tonsure and risen to high rank in their respective Buddhist sects. When Shingen attempted to seize control of Shinano province they were set on a collision course. Stephen Turnbull chronicles the see-saw struggle between two men who epitomize the warrior daimyo from Japan's 'Warring States' period.