when was it founded?
28 November 1660
Royal Society
The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. Founded on 28 November 1660, it was granted a royal charter by King Charles II as "The Royal Society". It is the oldest national scientific institution in the world. The society fulfils a number of roles: promoting science and its benefits, recognising excellence in science, supporting outstanding science, providing scientific advice for policy, fostering international and global co-operation, education and public engagement. 

who gave the first lecture of the royal society UNANSWERABLE what is the objective of this society? Promoting science and its benefits, recognising excellence in science, supporting outstanding science, providing scientific advice for policy, fostering international and global co-operation, education and public engagement.
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Royal Society [SEP] Introduction
The members of Council and the President are elected from and by its Fellows, the basic members of the society, who are themselves elected by existing Fellows. As of 2016, there are about 1,600 fellows, allowed to use the postnominal title FRS (Fellow of the Royal Society), with up to 52 new fellows appointed each year. There are also royal fellows, honorary fellows and foreign members, the last of which are allowed to use the postnominal title ForMemRS (Foreign Member of the Royal Society). The Royal Society President is Venkatraman Ramakrishnan, who took up the post on 30 November 2015.