On November 28, 1660, a group of twelve men met at Gresham College in London to listen to a lecture by Christopher Wren. Afterward they decided to meet weekly to discuss scientific topics. Their organization, which continued to expand in membership, did not receive official recognition until 1662 when King Charles II granted them a royal charter. The group then became officially known as the Royal Society of London with the purpose of "improving natural knowledge." Most of the members were Christians and the society became a leading force for scientific inquiry.