Complex sentence: Under Charles I of England, the Puritans became a political force as well as a religious tendency in the country, and after the First English Civil War political power was held by various factions of Puritans.
Split into simpler sentences: Under Charles I of England, the Puritans became a political force as well as a religious tendency in the country. After the First English Civil War political power was held by various factions of Puritans.