ABSTRACT This paper examines a neglected aspect of the history of the early Royal Society. Though it’s first two Royal Charters of 1662 and 1663 did not contain any religious-political restrictions, its 3rd Royal Charter of 1669 did. For the grant of an investment property in Chelsea, and the right to appoint more than one Vice President, the 3rd Charter restricted the sale of the property in Chelsea back to the Crown, and all Presidents and Vice Presidents were required to (...) swear the Anglican religious-political state oaths of Allegiance and Supremacy before admission to the positions. Thus the Royal Society, for the first time, was placed under a similar oaths system as those covering state, corporation, and religious organizations. The paper analyses the chaotic events leading up to the passing of the 3rd Charter: the impact of the Fire of London, the Royal Society’s move to Catholic aristocrat Henry Howard’s Arundel House, its failed plan to build a permanent ‘college’ there, and its forced acceptance of both the oaths and the non-alienation of Chelsea College. The paper concludes with the aftermath, the replacement of the oaths by a statutory declaration in 1835, through an Act of Parliament. (shrink)