Why is Eratosthenes important in the history of geography?

Eratosthenes of Cyrene is a foundational figure in the history of geography, primarily because he is credited with first using the term Geographica as the title of his work in the 3rd century BCE. His contributions established early scientific standards for the discipline, most notably through his pioneering efforts to measure the size of Earth.12

By observing the angle of the sun at different locations—Syene and Alexandria—he calculated the Earth's circumference with remarkable accuracy for his time. This work demonstrated the vital intersection of astronomy and geography, a relationship that remained central to the field for centuries as scholars sought to accurately locate places on the globe. His intellectual legacy helped transition the study of the world from descriptive accounts of travel to a more rigorous, measurement-based scientific discipline.21