Puritans

Puritans, a name given to a body of clergymen of the Church of England who refused to assent to the Act of Uniformity passed in the reign of Queen Elizabeth, because it required them to conform to Popish doctrine and ritual; and afterwards applied to the whole body of Nonconformists in England in the 16th and 17th centuries, who insisted on rigid adherence to the simplicity prescribed in these matters by the sacred Scriptures. In the days of Cromwell they were, “with musket on shoulder,” the uncompromising foes of all forms, particularly in the worship of God, that affected to be alive after the soul had gone out of them.

Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)