四海 north south east west
History[]
Historically referred to the 4 major seas at the boundaries of the Han dynasty after conquering the Xiongnu:
- West Sea was Lake Balkash in Central Asia
- East Sea was East China Sea, Yellow Sea or Bohai Sea
- North Sea was Lake Baikal in Siberia
- South Sea was the South China Sea
In literature, they are used to refer to the four cardinal boundaries of the world
The Han dynasty greatly expanded the unified territory of China, winning key battles such as the Battle of Zhizhi and the Battle of Mobei in the Han-Xiongnu war.
https://en.wikipedia.org/wiki/Four_Seas
Trivia[]
Term 四海 also used in One Piece, translated as 'All Blue' with each of the seas called North Blue, South Blue, East Blue, West Blue