DuringTrong thethời [[HanNhà DynastyHán]], YunmengĐầm Marshlầy lớn Vân Mông (雲夢大澤; yun2 meng4 da4 ze2) nằm phía bắt hồ Động Đình, ở tỉnh Hồ Bắc là nơi chứa lũ của sông Dương Tử, which lies to the north of Dongting Lake in Hubei Province, served as the main flood-basin of the Yangtze. The rich sediment of the marsh attracted farmers. Embankments were built, keeping the river out, and the Dongting Lake area south of the Yangtze gradually became the river's main flood-basin.
At that time, Dongting Lake was China's largest lake. Because of its size, it gained the name ''Eight-hundred-li-Dongting'' (八百里洞庭). Nowadays, it is the second-largest, after [[Poyang Lake]] (鄱陽湖), as much of the lake has been turned into farmland.
