Born Gerard de Cremere (or Kremer) in Rupelmonde. "Mercator" is the Latinized form of his name. It means "seller" or "marketer". Educated in 's-Hertogenbosch and at the University of Louvain. He travelled extensively, which provoked a keen interest in geography. He returned to Louvain and worked with Gemma Frisius and Gaspar Myrica. They worked together from 1535 to 1536 to construct a terrestrial globe. Later, Mercator produced a map of Palestine (1537), another map of the world (1538) and a map of Flanders (1540).
Mercator was charged with heresy in 1544 and spent seven months in prison. In 1552, he moved to Duisburg where he opened a cartographic workshop. He completed a six-panel map of Europe (1554) and he taught mathematics. He produced more maps and he was appointed Court Cosmographer to Duke Wilhelm of Cleve in 1564. He devised a new projection and first used it in 1569, it had parallel lines of longitude to aid navigation by sea, as compass courses could be marked as straight lines. He took the word atlas to describe a collection of maps, and encouraged Abraham Ortelius to compile the first modern world atlas, Theatrum Orbis Terrarum in 1570. He produced his own atlas in a number of parts, the first of which was published in 1578 and consisted of corrected versions of the maps of Ptolemy (though introducing a number of new errors). Maps of France, Germany and the Netherlands were added in 1585 and of the Balkans and Greece in 1588, further incomplete maps were published in 1594 after his death.