The Art of War, by Sun Tzu.

The Art of War is an ancient Chinese military treatise from around the 5th century BC by Sun Tzu ("Master Sun"). It is composed of 13 chapters, each one devoted to a different set of skills or art related to warfare and how it applies to military strategy and tactics.

For almost 1,500 years The Art of War was the lead text in an anthology that was formalized the Seven Military Classics by Emperor Shenzong in 1080. The treatise remains the most influential strategy text in East Asian warfare and has influenced both Far Eastern and Western military thinking, business tactics, legal strategy, lifestyles and beyond.

The book contains a detailed explanation and analysis of the 5th-century BC Chinese military, from weapons and strategy to rank and discipline. Sun also stressed the importance of intelligence operatives and espionage to the war effort. Considered one of history's finest military tacticians and analysts, his teachings and strategies formed the basis of advanced military training for millennia to come. (From Wikipedia).