Takeda Shingen in the context of "Battles of Kawanakajima"

The Sengoku period (戦国時代, Sengoku jidai; Japanese pronunciation: [seŋ.ɡo.kɯ (d)ʑiꜜ.dai, -ŋo.kɯ-] lit. 'Warring States period') was the period in Japanese history in which civil wars and social upheavals took place almost continuously in the 15th and 16th centuries. The Kyōtoku incident (1454), Ōnin War (1467), or Meiō incident [ja] (1493) are generally chosen as the period's start date, but there are many competing historiographies for its end date, ranging from 1568, the date of Oda Nobunaga's march on Kyoto, to the suppression of the Shimabara Rebellion in 1638, deep into what was traditionally considered the Edo period. Regardless of the dates chosen, the Sengoku period overlaps substantially with the Muromachi period (1336–1573).

This period was characterized by the decline of the Ashikaga shogunate, the de facto central government, while the sengoku daimyo (戦国大名, feudal lords of the Sengoku period), local power-holders, acquired greater political influence. The people rebelled against the feudal lords in revolts known as Ikkō-ikki (Ikkō-shū uprising).

Nagao Kagetora (長尾 景虎; February 18, 1530 – April 19, 1578), later known as Uesugi Kenshin (上杉 謙信), was a Japanese daimyō (magnate). He was born in Nagao clan, and after adoption into the Uesugi clan, ruled Echigo Province in the Sengoku period of Japan. He was one of the most powerful daimyō of the Sengoku period. Known as the "Dragon of Echigo", while chiefly remembered for his prowess on the battlefield as a military genius and war hero, Kenshin is also regarded as an extremely skillful administrator who fostered the growth of local industries and trade, as his rule saw a marked rise in the standard of living of Echigo.

Kenshin is famed for his honourable conduct, his military expertise, a long-standing rivalry with Takeda Shingen, his numerous defensive campaigns to restore order in the Kantō region as the Kanto Kanrei, and his belief in the Buddhist god of war Bishamonten. Many of his followers and others believed him to be the avatar of Bishamonten and called Kenshin the "God of War".

Toyohara Chikanobu (豊原周延; 1838–1912), better known to his contemporaries as Yōshū Chikanobu (楊洲周延), was a Japanese painter and printmaker who was widely regarded as a prolific woodblock artist during the Meiji epoch.

Murakami Yoshikiyo (村上 義清, 1501–1573) was a Japanese samurai from the Murakami clan and retainer of the Uesugi clan during the Sengoku period of the 16th century. Yoshikiyo followed in fighting against both Takeda Nobutora and his son Takeda Shingen. Yoshikiyo was also a very close ally under Uesugi Kenshin and one of Shingen's bitterest opponents for his high kill-counts in their conflicts.

Before Murakami came into conflict with Takeda, they had good diplomatic relations as Yoshikiyo had sent back Oi Sadataka, a common enemy of both Murakami and Takeda when he was captured in Murakami's domain back to Takeda's base city of Kōfu as a prisoner for execution.

The Takeda clan (武田氏, Takeda-shi) was a Japanese samurai clan active from the late Heian period until the late 16th century. The clan was historically based in Kai Province in present-day Yamanashi Prefecture. The clan reached its greatest influence under the rule of Takeda Shingen, one of the most famous rulers of the period.

Takeda Nobutora (武田 信虎; February 11, 1494 – March 27, 1574) was a Japanese daimyō (feudal lord) who controlled the Province of Kai, and fought in a number of battles of the Sengoku period. He was the father and predecessor of the famous Takeda Shingen.