John Flamsteed was an English astronomer born on August 19, 1646. He is best known for being the first Astronomer Royal, a position he held from 1675 until his death in 1719. Flamsteed's work focused on accurately mapping the stars and planets, which was crucial for navigation and understanding the universe. Flamsteed published his most significant work, the Historia Coelestis Britannica, in 1725, after his death. This catalog contained detailed observations of over 3,000 stars, laying the groundwork for modern astronomy. His contributions helped improve the accuracy of celestial navigation and inspired future astronomers like Isaac Newton.