Takeda Shingen (武田 信玄?, December 1, 1521 – May 13, 1573), of Kai Province, was a preeminent daimyo in feudal Japan with exceptional military prestige in the late stage of the Sengoku period.
Shingen was called "Tarō" (a commonly used pet name for the eldest son of a Japanese family) or "Katsuchiyo" (勝千代) during his childhood. When he celebrated his coming of age, he was given a formal name of "Harunobu" (晴信), which included a character from the name of Ashikaga Yoshiharu (足利義晴), the 12th Ashikaga Shogun. It was a common practice in feudal Japan for a higher-ranked warrior to bestow a character from his own name to his inferiors as a symbol of recognition. From the local warlord's perspective, it was glorious to receive a character from the shogunate, although the authority of the latter had greatly degenerated in the mid-16th century.
Both the Ashikaga and the Takeda clans descended from the noble Minamoto (源) clan. Technically, Harunobu, as well as his forefathers, had borne the surname of Minamoto. Therefore, Harunobu would be referred to as "Minamoto-no Harunobu" (源晴信) in official records kept by the Imperial Court when he was conferred the official title of "Daizen Dayu" (大膳大夫). The Imperial Court had maintained a system of ritsuryō (律令) that was parallel to the shogunate apparatus.
In 1559 Harunobu chose to live a pabbajja life and received a dharma name, Shingen (信玄), from his Buddhist master. The kanji of "Shingen" can also be pronounced as "Nobuharu," which is the inversion of his official name, Harunobu. In ancient times, such stylish/religious names of recognized Japanese aristocrats/warriors/officials would be read in "onyomi" (音読み), the Chinese-styled pronunciation, instead of "kunyomi" (訓読み), the indigenous Japanese pronunciation. Although widely known by the dharma name, Takeda Shingen's formal name remained "Harunobu" throughout the rest of his life.
Shingen is sometimes referred to as "The Tiger of Kai" (甲斐の虎) for his martial prowess on the battlefield. His primary rival, Uesugi Kenshin (上杉謙信), was often called "The Dragon of Echigo" (越後の龍) or also "The Tiger of Echigo" (越後の虎).
Takeda Shingen was the first born son of Takeda Nobutora (武田信虎), leader of the Takeda clan, and daimyo of the province of Kai.