Henry Parker was the fourth son of Nicholas Parker of Ratton and is believed to have died in Ireland. Matriculating at St Edmund's Hall, Oxford in 1622, he graduated BA in 1625 and MA in 1628. He was called to the Bar at Lincoln's Inn in 1637. During the civil war he committed himself to the Parliamentary cause, later lending his service to the revolutionary government as a civil servant and political theorist. In July 1642 he was appointed secretary to the army under Essex. He is believed to have served as secretary to the Committee of Safety in 1642–3, before petitioning the Commons for the registrarship of the Prerogative Office in November 1643. He was rejected in favour of Michael Oldsworth, but they were jointly appointed in 1649.
From The Continuum Encyclopedia of British Philosophy in Oxford Reference.