As well as his love of the arts, Charles II was a major patron of the sciences. In his reign, the Royal Society was granted its charter and the Royal Observatory established in Greenwich Park. Here, Dr Louise E. Devoy, Curator of the Royal Observatory Greenwich, discusses his role in the origins of this important institution.

A new chapter in British science

On 4 March 1675, Charles II signed a Royal Warrant to establish the role of the Astronomer Royal in a bid to resolve the challenge of navigating at sea:

Whereas, we have appointed our trusty and well-beloved John Flamsteed, master of arts, our astronomical observator, forthwith to apply himself with the most exact care and diligence to the rectifying the tables of the motions of the heavens, and the places of the fixed stars, so as to find out the so much-desired longitude of places for the perfecting the art of navigation

Charles II, Warrant

The king was no stranger to science. Shortly after the Restoration, he had already assembled his own private laboratory at St. James’ Palace, in a bid to explore his interests in alchemy and chemistry. This interest in science became more apparent in July 1662 when he granted a Charter to a group of gentlemen who met weekly at Gresham College to discuss science (‘natural philosophy’) and subject new ideas to experimental rigour with the motto Nullius in verba (‘Take nobody’s word for it’).

The challenge of improving navigation at sea was a major concern for this newly-formed Royal Society but the real impetus for the appointment of an ‘astronomical observator’ was the arrival of the French astronomer Sieur de St Pierre in December 1674. He claimed that he had improved the ‘lunar distance’ method of navigation in which a mariner could measure the angles between the Moon and nearby bright stars to determine longitude at sea. The king ordered the Royal Society to investigate and they subsequently appointed John Flamsteed, a talented young astronomer from Derby, to assess St Pierre’s claims.

After much observation and calculation, Flamsteed concluded in February 1675 that there was insufficient accurate astronomical data available to validate St Pierre’s claims and transform the lunar-distance method into a viable navigational technique. This result spurred the king into action, first with the warrant to appoint Flamsteed as ‘astronomical observator’, followed by another on 22 June that same year to instigate the construction of an observatory:

Whereas, in order to the finding out of the longitude of places for perfecting navigation and astronomy, we have resolved to build a small observatory within our park at Greenwich, upon the highest ground, at or near the place where the castle stood, with lodging-rooms for our astronomical observator and assistant.

Charles II, Warrant establishing the Royal Observatory in Greenwich

The site of the abandoned Greenwich Castle was an ideal choice for several reasons:

• The parkland belonged to the Crown and was essentially free
• The hill offered good views of the horizon to observe the rising and setting of the stars
• The rural location offered good seeing conditions away from London’s smog
• The Astronomer Royal could still reach Court and the Royal Society by river

Thanks to his patron, Sir Jonas Moore, Flamsteed made an immediate start to his observations by occupying one of the turrets of the White Tower, at the Tower of London, in April 1675. Two other Royal Society members, Christopher Wren and Robert Hooke, were charged with the design and construction of the new observatory and Flamsteed eventually occupied the site in the summer of 1676.

There’s no record of the king visiting his new scientific institution but, thanks to his foresight and interest in the subject, British astronomers were able to contribute to the development of navigation that firmly put Greenwich on the map.