Military history of the Northern and Southern dynasties
The military history of the Northern and Southern dynasties encompasses the period of Chinese military activity from 420 to 589. Officially starting with Liu Yu's usurpation of the Jin throne and creation of his Liu Song dynasty in 420, it ended in 589 with the Sui dynasty's conquest of Chen dynasty and reunification of China proper.
Source: Wikipedia — Military history of the Northern and Southern dynasties (CC BY-SA 4.0)