Gerardus Mercator was a cartographer famous for having invented the "Mercator Projection." The novelty was that the longitudes' lines were parallel, and this made the navigation easier because the direction of the compass could be marked with straight lines.
He was one of the firsts to use the word "Atlas" to describe a collection of maps, and encouraged Abraham Ortelius to make the first modern Atlas.
Mercator began then to work on his own Atlas, which was a corrected version of Ptolemy's Maps. Unfortunately, Mercator died in 1594 without completing his work. It was his son who finished the Atlas, publishing all the maps they had prepared together.