The history of meridians hints at an alternative history of the world—geographical, political, and plural—that tells the story of how we became global.

The history of meridians may well be the greatest adventure of scholarly humanity. It is not merely a chronicle of mathematical calculations, astronomy, or cartography; it is also a story of individual adventures featuring sailors, academics, surveyors, diplomats, soldiers, geometricians, geodesists, clockmakers, and astronomers. By organizing space and delimiting borders, these reference lines have greatly contributed to the building of empires and the consolidation of modes colonial domination up through their apogee in the early 20th century.