Ruscelli's double hemisphere world map was the first one in an atlas with two separate hemispherical maps.
In the first edition of 1561, the title of the map was trimmed.
No southern continent is shown. Nearly twenty-five years later the plate was amended by the addition of a southern continent.

Giacomo Gastaldi (c. 1500 – 1566)

Giacomo Gastaldi was born in Villafranca, in Piedmont, to a wealthy family. Although he is considered one of the greatest cartographers of the sixteenth century, the events of his life and his professional training in the field of cartography are unknown to us until he arrives in Venice, where, in 1539, he obtained a perpetual printing privilege from the Venetian Senate.

One of the first Venetian contacts took place with the geographer and humanist Giovanni Battista Ramusio, with whom he collaborated. At the beginning of the 1540s, Gastaldi was already an established cartographer and began to work on a series of maps first published separately and then included in the Italian edition of Ptolemy's Geography of 1548, together with others made from scratch.

By the 1540s he had developed his own distinctive style of copper engraving for his increasingly prolific output of maps. His maps were used as a source by many mapmakers including Camocio, Bertelli, Forlani, Ramusio, Cock, Luchini and Ortelius.

With the support of his influential friendships, Gastaldi also obtained public positions: in 1549, the Council of Ten commissioned him to make a large map of Africa, for a wall from the armoury in the Doge's Palace and, again for the same room, one map of Asia and one of North America.

It is difficult to quantify the number of maps he produced; more than a hundred have been attributed to him.
Paolo Forlani collaborated for a long time with Gastaldi and published numerous counterfeits and not authorized editions.
Gastaldi died in Venice on 14 October 1566.