After Emperor Taizong of Tang, Li Shimin, dies, his soul unexpectedly transmigrates a thousand years into the future and takes over the body of Zhao Gou, emperor of the Southern Song. The Southern Song is impoverished and weak, with Jin forces eyeing it from beyond its borders and treacherous ministers holding sway at home. Drawing on his exceptional political wisdom, military talent, and decisive methods, Li Shimin reforms the court, overhauls the military, develops the economy, and repels foreign enemies. He leads the Southern Song army to repeated victories, gradually recovers lost territory, and reunifies and revives the nation. Along the way, he faces power struggles at court, diplomatic crises abroad, and all manner of natural and man-made disasters. Yet he never wavers in his resolve, transforming the Southern Song from a declining state into a prosperous and thriving empire. He creates an unprecedented golden age and writes a sweeping legend.