The Geological Society of London, known commonly as the Geological Society, is a learned society based in the United Kingdom. It is the oldest national geological society in the world and the largest in Europe, with more than 12,000 fellows.

The Society was founded in 1807 by a group of geologists who were interested in promoting the study of the Earth. The Society’s first meeting was held at the Freemasons’ Tavern in London on 13 November 1807. The Society’s first president was George Bellas Greenough.

The Society’s aims are to improve knowledge and understanding of the Earth, to promote Earth science education and awareness, and to promote professional excellence and ethical standards in the work of Earth scientists, for the public good.

The Society has 24 specialist groups and 15 regional groups which serve as an opportunity for those with specific interests to meet and discuss their subject or region. They are all free for members to join and some are open to non-members.

The society publishes two of its own journals, the (formerly Quarterly) Journal of the Geological Society and the Quarterly Journal of Engineering Geology & Hydrogeology. It also publishes the magazine Geoscientist for Fellows, and has a share in Geology Today, published by Blackwell Science.

The Geological Society of London is a leading international organization for Earth scientists. The Society plays a vital role in promoting the study of the Earth and in communicating Earth science to the public.

According to the Internet