Vicar of Bray
(The). Let who will be king, I will be vicar of Bray still. Brome says of Simon Alleyn that he “lived in the reigns of Henry VIII., Edward VI., Mary, and Elizabeth. In the first two reigns he was Protestant, in Mary's reign he turned Papist, and in the next reign recanted- being resolved, whoever was king, to die Vicar of Bray.” (1540-1588.) Others say it is Pendleton.
Ray refers to Simon Symonds, a vicar who was Independent in the Protectorate, Churchman in the reign of Charles II., Papist under James II., and Moderate Protestant under William and Mary.
The well-known song, “I will be Vicar of Bray,” was written by an officer in Colonel Fuller's regiment. This vicar lived in the reigns of Charles II., James II., William III., Anne, and George I.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894
More on Vicar of Bray from Infoplease: