Fūrinkazan (風林火山), literally "Wind, Forest, Fire, Mountain", is a popularized version of the battle standard used by the Sengoku period daimyo Takeda Shingen. The banner quoted four phrases from Sun Tzu's The Art of War: "as swift as wind, as silent as forest, as fierce as fire, as unshakable as mountain."
The original version of the banner is mentioned in the Kōyō Gunkan, a record of the military exploits of the Takeda clan. It is based on four phrases from Sun Tzu, which in the original Chinese appear in two consecutive passages:
Chapter 7, passage 17: “故其疾如風，其徐如林“ Let your rapidity be that of the wind, your silence that of the forest.
Chapter 7, passage 18: “侵掠如火，不動如山“ In raiding and plundering be like fire, be immovable like a mountain.
The complete verse (chapter 7 passages 17–19) is "故其疾如風、其徐如林、侵掠如火、難知如陰、不動如山、動如雷霆", and as such it is notable that fūrinkazan omits "難知如陰" Be as hard to know as the shadow and "動如雷霆" Move as fast as lightning.
The well-known four-character version appears to be a later invention. Historian Masaya Suzuki, citing the work of an authority on the military insignia of the time, notes that there is no evidence in the historical record for the four-character phrase, and points out that it became popular with the publication of a historical novel of the same name by Yasushi Inoue in 1953.
- 鈴木眞哉 (2009). "「風林火山」の旗印の怪しさ" [Historicity of the fūrinkazan banner]. 戦国武将のゴシップ記事 [Feudal warlord hearsay stories] (in Japanese). Tokyo: PHP. ISBN 978-4569709550.