The Cinque Ports (Derivation: Old French; cink porz) - pronounced sink ports – were originally the 12th century seaports of Hastings, Sandwich, Dover, Romney and Hythe that were granted special privileges for providing ships, equipment and men for the defence of the coasts of Kent and Sussex in England. They were the closest England ever had to a European-type league or confederacy of towns with a like-minded purpose.
Later, the five were joined by Winchelsea and Rye and, later still, other ports became sort of “branch members” so that the association ultimately totalled up to about forty. Their importance declined rapidly in the 17th century with the rise of a formal national navy and the silting up of several of the harbours, until today it only exists in the title of the “Warden of the Cinque Ports”, a purely ceremonial position revived in the early 20th century in conjunction with the Governorship of Dover Castle; and given to retired worthies, such as ex Conservative prime ministers and even the Queen Mother.
Reference: “Brewer’s Britain and Ireland”