Yarmouth, Great, a port and parliamentary and municipal borough in Norfolk, on the Yare, including for purposes of representation Little Yarmouth and Gorleston in Suffolk. Unknown until after the Conquest, it received a charter from King John, and was fortified by Henry III. It is the chief seat of the herring fishery, but many other kinds of fish are sent to the London markets. The harbour and quays at the mouth of the Yare accommodate vessels of 900 tons. A large general trade is done.