Julian Romane examines the military events behind the emergence of the Sui and Tang dynasties in the period 581-626 AD. Narrating the campaigns and battles, he analyses in detail the strategy and tactics employed, a central theme being the collision of the steppe cavalry with Chinese infantry armies. By the fourth century AD, horse nomads had seized northern China. Conflict with these Turkic interlopers continued throughout the 5th and most of the 6th century. The emergence of the Sui dynasty (581-618) brought some progress but internal weakness led to their rapid collapse.