 This information was sometimes collected and written down in a pilot's handbook, known as a "portolano" ("port book", in Italian, equivalent to the Greek "periplus", the Portuguese "roteiro" and the English "rutter").These handbooks were used to construct a class of nautical maps known as portolan charts.Portolan charts began being produced in Genoa in the late 13th century, and soon spread to Venice and Majorca.