A Prime Commemorative

The Royal Mint has issued a 2-pound coin to honor the 350th anniversary of the Royal Observatory, the first state-funded, purpose-built scientific institution in Britain. The commemorative coin pays tribute to the observatory with the dial of the Shepherd Gate Clock on the reverse. The constellation Ursa Minor and Polaris (or North Star) appear in the background, with the prime meridian line on a globe in the foreground. THE ROYAL OBSERVATORY GREENWICH and the years 1675 and 2025 surround the central design. The coin also includes the edge inscription PERFECTING THE ART OF NAVIGATION. The Royal Mint will contribute a portion of the coin’s sales to the Trustees of the National Maritime Museum, a charity based in England and Wales.

History of the Royal Observatory 

King Charles II commissioned the Royal Observatory in Greenwich, England, in 1675. Construction began quickly with a small budget. John Flamsteed, the first astronomer royal, laid the observatory’s first stone in August 1675. Since then, the scientific institution has played a critical role in navigation and timekeeping, serving as the historic source of the prime meridian at 0 degrees longitude. For centuries, astronomers at Greenwich observed the stars to improve navigation at sea, and in 1884, world leaders met in Washington, D.C., to divide the world into 24 hourly time zones, each measured from the Greenwich meridian. 

Today, the observatory is a UNESCO World Heritage site and remains the home of Greenwich mean time and the prime meridian. It primarily operates as a museum and tourist attraction. Visitors can tour the original observatory and planetarium, and view attractions like the Great Equatorial Telescope and the Shepherd Gate Clock.

A version of this article appears in the August 2025 issue of The Numismatist (money.org).