Gerardus Mercator, married (to Barbara Schellkens) with six children, moves in 1552 at age forty to the Duchy of Cleves to become a mapmaker and lecturer at the University of Duisburg.

Once here, he becomes a well-known figure, and assists the duke in establishing a grammar school by helping to design its curriculum.

After establishing a cartographic workshop and engaging his own engravers, he returns to his main interest.

He publishes a superb six-panel map of Europe in 1554.