Gerardus Mercator

Born into a Catholic family in Flanders in 1512, Mercator built his reputation as a maker of globes and scientific instruments, selling them across Europe for six decades. He rarely traveled; his geography came from a library of over a thousand books and correspondence in six languages with merchants, seamen, and scholars. In 1569 he published the world map that bore his name - a projection representing sailing courses of constant bearing as straight lines, revolutionizing navigation. Accused of heresy by Catholic authorities, he spent six months in prison before his release, then left Leuven for the more tolerant Duisburg, where he spent his final thirty years. There he produced over a hundred new regional maps and assembled them into his 1595 Atlas - the first use of that word for a book of maps, named for the Titan he considered the first great geographer. He died in Duisburg in 1594, leaving behind not just charts but chronologies, theological writings, and a method for flattening the globe that cartographers never abandoned.