the charter between dartford and gravelines was signed in gravelines on the 22 september 1991 by the mayor, councillor tony gillham, on behalf of dartford borough council and councillor a. may on behalf of the dartford and district twinning association together with the mayor of gravelines, monsieur a. denvers and monsieur c. marquis, chairman of their jumelage (which is gravelines' equivalent to dartford's twinning association).