The Tudor Reformation resulted in widespread dissatisfaction. Many Protestants considered the Reformation unfinished as the established Church of England retained some of the rights and practices of Catholic worship. Meanwhile, Catholics were oppressed and marginalised.
Scotland was similarly divided between strict Protestants, (Calvinists) and staunch Catholics, while in Ireland most of the population was Catholic, who were governed by a minority of English, and Scottish Protestants.
Professor Hughes discusses, how this religious mix, created a climate of distrust and division, which ultimately resulted in civil war.