Northern and Southern Courts (Japan, 1336-1392)
Refers to the period of divided imperial courts in Japan. Often used in historical contexts.
The Nanboku-chō period was an important turning point in Japanese history.
Northern and Southern Dynasties (China, 420-589)
Refers to the period of division in Chinese history. Less common than the Japanese sense in everyday Japanese.
The Chinese Northern and Southern Dynasties period was also a time when Buddhism spread.