The essay introduces and comments on a very special document. It is a report of the Sienese mercantile court (a unicum of its kind for the XIV century), recopied in the register of a Florentine notary: ser Lando di Fortino dalla Cicogna. In a couple of folios appear Mediterranean routes that connect Naples with Barcelona, merchants and ship-owners of various Italian cities, the officials of the port of Talamone, the judges of Mercanzia di Siena, the vicar of the bishop of Florence and his closest collaborators.