DURING THE AGE OF DISCOVERY, in the autumn of 1550, a little-known public servant in the Venetian government, Giovambattista Ramusio, anonymously published Navigationi et Viaggi (Journeys and Navigations). Containing a wealth of geographical information new to Europeans - from the diaries of Marco Polo to detailed reports from the Muslim diplomat Leo Africanus - it became the basis of the world map we still use today. In an enthralling narrative, This Earthly Globe brings to life the man who used all his political skill to democratize knowledge and show how the world was much larger than anyone previously imagined, and in doing so chronicles the birth of modern geography.