César-François Cassini, born in 1714, was a prominent French astronomer and geodesist. He is best known for his work in mapping the geography of France and for his contributions to the field of triangulation, which helped improve the accuracy of maps. Cassini was a member of the Cassini family, a dynasty of astronomers, and he succeeded his father, Jacques Cassini, in the role of the royal astronomer. Cassini's most notable achievement was the creation of the first detailed topographic map of France, known as the Cassini Map. This extensive project took several decades and involved meticulous measurements across the country. His work laid the foundation for modern cartography and significantly advanced the understanding of Earth's shape and size.