Colonel Nathaniel Rich (c. 1620–1622 to 1701–1702) was a member of the landed gentry from Essex, who sided with Parliament during the Wars of the Three Kingdoms and was "an example of those pious Puritan gentlemen who were inspired by the ideals of the English Revolution". Appointed a colonel in the New Model Army in 1645, then elected MP for Cirencester in 1648, he was a close associate of Oliver Cromwell until the two fell out due to his association with the Fifth Monarchists, a radical religious group that opposed the latter's appointment as Lord Protector in 1653.