Known as the "Tiger of Kai" for his ferocity on the battlefield, Takeda Shingen was one of the most brilliant and colorful figures of the Warring States Period. In a long and storied career, he distinguished himself not only as one of the truly great tacticians of his time but also as a wise and capable administrator.

Born in 1521, Shingen was the eldest son of Nobutora, a competent military leader but also a deeply unpopular one. Little is known about the boy's childhood, except that his father seems to have taken an early and intense dislike towards him.

At the age of just 15, Shingen gained his first battle experience, joining his father's campaign against former retainer Hiraga Genshin. Attacking Genshin's castle of Un no Kuchi, Nobutora's forces were repeatedly beaten back and as the first snow began to fall, he decided to abandon the attempt. With the Takeda army in retreat, Shingen suddenly broke off from the main body with a small band of followers to launch a final surprise attack, succeeding in catching the enemy off guard and quickly capturing the castle. The unexpected victory only served to peak Nobutora's resentment, and matters between them came to a head in 1540 when Nobutora attempted to pass over Shingen as heir in favor of his younger brother Nobushige. At this, the family's most senior retainers turned on Nobushige and forced him into exile. At the age of 20 and without a drop of blood spilled, Shingen was now chief of one of the country's most powerful warrior clans.

Upon taking command, Shingen immediately turned his attention toward expanding the reach of his clan by seizing new territory to the north in Shinano, modern-day Nagano Prefecture. This soon brought him into conflict with a coalition of clans including the Murakami and Suwa, but rather than engage them directly, Shingen chose to feign weakness by withdrawing to his fortress at Tsutsujigasaki in present-day Kofu City where he appeared to be preparing for a final stand. The Shinano samurai took the bait and attacked, only to be caught in the open and soundly defeated by Shingen's much smaller force at Sezawa, just north of the border. Later the same year, he followed up on this victory by beginning a relentless advance into Shinano that would continue for over a decade.

The next few years brought two of the most famous elements of the legend we know today - the dharma name Shingen, bestowed by his Buddhist teacher, and the beginning of a lifelong rivalry with Uesugi Kenshin, daimyo of Echigo province, corresponding today with the mainland portion of Niigata Prefecture. Kenshin had largely ignored the calls for aid from the Murakami who were his vassals, but as Shingen continued to swallow up Shinano province, could no longer avoid confronting the looming threat at his southern border. The two armies met in July and October of 1553, but such was the two great generals' mutual respect that neither would commit to an all-out attack, and after warily testing one another's defenses, both withdrew. This would set the pattern for a series of encounters in the coming years at different parts of the Kawanakajima plain. Of these, only the fourth in 1561 resulted in all-out battle, with both sides suffering heavy casualties before reaching stalemate and again withdrawing.

The 1560s brought two serious plots against Shingen's rule - the second in 1565 by his own son Yoshinobu, who he had imprisoned and would be dead within two years, though whether by forced suicide or natural causes is unclear. Now with all of Shinano under his control, Shingen shifted focus towards internal affairs, carrying out only limited operations in Kozuke (modern-day Gunma Prefecture) and the Hida Mountains while consolidating his rule at home. It was during this time that he completed perhaps the boldest civil undertaking of his time, constructing a network of dikes along the Fuji River to limit the damage caused by flooding, many of which survive to this day.

In 1568, Shingen was ready to resume his efforts at expansion and launched a new campaign to the south into Suruga Province, the central part of what is today Shizuoka Prefecture against an internally divided Imagawa Clan. For this, Shingen may have had any number of motivations but it is particularly likely that he was at this point already looking ahead to a confrontation with the rising power of Oda Nobunaga and his ally Tokugawa Ieyasu. Shingen was able to quickly defeat the Imagawa, but was held up by the Hojo Clan of neighboring Sagami province, now Kanagawa Prefecture. Although ultimately inconclusive, the campaign ended with the Hojo capital of Odawara under seige, and in 1570 when the Hojo leader Ujiyasu died, his heir Ujimasa made peace. Now adding Suruga to his extensive territory, Shingen had become the dominant power in the east of Japan, and the only warlord in a position to challenge Nobunaga.

With nothing standing between Shingen and his own lands, Ieyasu took the provocative step of moving his base of operations to Hamamatsu in Totomi Province, close to Shingen's new territory in Suruga. In 1572 Shingen invaded, defeating Ieyasu at the battle of Mitagahara from which Ieyasu only narrowly escaped with his life. With his enemies on the defensive, there seemed to be no limit to what Shingen might achieve, until in one of history's great upsets he fell ill or was struck by a sniper's bullet later the same year while laying seige to Noda Castle in Mikawa, and died shortly after.

Shingen was a colossal figure in life, but like many warlords of the Sengoku his efforts were not enough to secure the future of his family. Though capable and ambitious, his son Katsuyori was later defeated and committed suicide, with Ieyasu later taking control of Shingen's home fief of Kai. Despite the lack of a lasting political or dynastic legacy, Shingen continues to enjoy folk-hero status today, especially in the city of Kofu, where his life is celebrated every April in the Shingen-Ko festival. Shingen would also leave a lasting impression on Japanese governance, with Ieyasu adopting many of his policies and administrative systems in the later Tokugawa Shogunate.