With the simultaneous release of 4567 balloons from the Courtyard of Burlington House, Mayfair on 10 January 2007, The Geological Society of London will celebrate not only its own 200th birthday, but also the 4567 millionth birthday of Planet Earth. The Geological Society of London was founded by 13 men on Friday 13th November 1807, in The Freemason’s Tavern, Long Acre, a pub which once stood on the site of what is now the Connaught Rooms in Great Queen Street. In its 200 years the Society has seen its subject achieve maturity (with the unifying theories of plate tectonics and the “Gaian” Earth System) in a shorter time than any other science.