During the Warring States period in China, Li Xin and Piao are two brother-like youngsters who dream of becoming Great Generals, despite their low status as orphaned slaves. One day, they encounter a man of nobility, who gives Piao an opportunity to undertake an important duty within the state of Qin's royal palace. Parting ways, Xin and Piao promise each other to one day become the greatest generals in the world. However, after a fierce coup d'état occurs in the palace, Xin meets with a dying Piao, whose last words spur him into action and lead him to encounter the young and soon-to-be king of Qin, Ying Zheng.

Although initially on bad terms, Xin and Zheng become comrades and start on a path filled with trials and bloodshed. Zheng's objective is to bring all the warring states under Qin, and Xin seeks to climb to the very top of the army ranks. Against a backdrop of constant tactical battle between states and great political unrest, both outside and within the palace, the two endeavor towards their monumental ambitions that will change history forever.