Gerardus Mercator

A Biography of Flemish Cartography Gerardus Mercator


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Gerardus Mercator was a Flemish cartographer, philosopher, and geographer who is best known for his creation of the Mercator map projection. On the Mercator projection parallels of latitude and meridians of longitude are drawn as straight lines so that they are useful for navigation. Mercator was also known for his development of the term “atlas” for a collection of maps and his skill in calligraphy, engraving, publishing and making of scientific instruments (Monmonier 2004). In addition, Mercator had an interests in mathematics, astronomy, cosmography, terrestrial magnetism, history and theology (Monmonier 2004)

Today Mercator is mostly thought of as a cartographer and geographer and his map projection was used for hundreds of years as the quintessential way to depict the Earth. Many maps using the Mercator projection are still used in classrooms today, despite the development of newer, more accurate map projections.

Early Life and Education

Gerardus Mercator was born on March 5, 1512 in Rupelmond, County of Flanders (modern-day Belgium). His name at birth was Gerard de Cremer or de Kremer (Encyclopedia Britannica). Mercator is the Latin form of this name and means “merchant” ( Mercator grew up in the Duchy of Julich and was educated Hertogenbosch in the Netherlands where he received training in the Christian doctrine as well as Latin and other dialects. 

In 1530 Mercator began studying at the Catholic University of Leuven in Belgium where he studied humanities and philosophy. He graduated with his master’s degree in 1532. Around this time Mercator began to have doubts about the religious aspect of his education because he could not combine what he was taught about the origin of the universe with that of Aristotle’s and other more scientific beliefs (Encyclopedia Britannica). After his two years away in Belgium for his master’s degree, Mercator returned to Leuven with an interest in philosophy and geography.

At this time Mercator began studying with Gemma Frisius, a theoretical mathematician, physician and astronomer, and Gaspar a Myrica, an engraver and goldsmith. Mercator eventually mastered mathematics, geography and astronomy and his work, combined with that of Frisius and a Myrica made Leuven a center for the development of globes, maps and astronomical instruments (Encyclopedia Britannica).

Professional Development

By 1536 Mercator had proven himself as an excellent engraver, calligrapher, and instrument maker. From 1535-1536 he participated in a project to create a terrestrial globe and in 1537 he worked on a celestial globe. Most of Mercator’s work on the globes consisted of the labeling of features with italic lettering. 

Throughout the 1530’s Mercator continued to develop into a skilled cartographer and the terrestrial and celestial globes helped to cement his reputation as the leading geographer of that century. In 1537 Mercator created a map of the Holy Land and in 1538 he made a map of the world on a double heart-shaped or cordiform projection (Encyclopedia Britannica). In 1540 Mercator designed a map of Flanders and published a manual on italic lettering called, Literarum Latinarum quas Italicas Cursoriasque Vocant Scribende Ratio

In 1544 Mercator was arrested and charged with heresy because of his many absences from Leuven to work on his maps and his beliefs toward Protestantism (Encyclopedia Britannica). He was later released due to university support and he was allowed to continue pursuing his scientific studies and print and publish books.

In 1552 Mercator moved to Duisburg in the Duchy of Cleve and assisted in the creation of a grammar school. Throughout the 1550’s Mercator also worked on genealogical research for Duke Wilhelm, wrote a Concordance of the Gospels, and compose several other works. In 1564 Mercator created a map of Lorraine and the British Isles.

In the 1560’s Mercator began to develop and perfect his own map projection in an effort to help merchants and navigators more effectively plan a course over long distances by plotting it on straight lines. This projection became known as the Mercator projection and was used on his map of the world in 1569.

Later Life and Death

In 1569 and throughout the 1570’s Mercator began a series of publications to describe the creation of the world through maps. In 1569 he published a chronology of the world from Creation to 1568 (Encyclopedia Britannica). In 1578 he published another which consisted of 27 maps that were originally produced by Ptolemy. The next section was published in 1585 and consisted of newly created maps of France, Germany and the Netherlands. This section was followed by another in 1589 that included maps of Italy, “Sclavonia” (the present-day Balkans), and Greece (Encyclopedia Britannica)

Mercator died on December 2, 1594, but his son aided in the production of the final section of his father’s atlas in 1595. This section included maps of the British Isles.

Mercator’s Legacy

Following its final section being printed in 1595 Mercator’s atlas was reprinted in 1602 and again in 1606 when it was named the “Mercator-Hondius Atlas.” Mercator’s atlas was one of the first to include maps of the world’s development and it, along with his projection remain as significant contributions to the fields of geography and cartography.

To learn more about Gerardus Mercator and his map projection, read Mark Monmonier’s Rhumb Lines and Map Wars: A Social History of the Mercator Projection.