1512-1594
Cartographer

Education. Gerhard Kremer was born in Flanders to German parents. He Latinized his family name to Mercator (Latin for Kremer, "merchant") when he matriculated at the University of Louvain in 1530. There he studied philosophy and theology, but also became interested in cartography and the then state-of-the-art technology for printing illustrations called copper-plate engraving.

Famed Mentor. After graduation he studied mathematics and astronomy privately with Gemma Frisius, a renowned humanist geographer and maker of terrestrial globes for navigation. In 1529 Frisius edited and revised Peter Apian's Cosmographia (1524), a description of Earth that was based on Ptolemy's Geography. He then published his own Gemma Phrysius de principiis astronomia et cosmographia (Principles of Astronomy and Cosmography, 1530). Frisius added to Apian's work a description of how to apply the method of triangulation to mapmaking, which was later used by Danish astronomer Tycho Brahe, and suggested that longitude at sea...