The Puritans were a group of English-speaking Protestants in the 16th and 17th centuries. Puritans thought that the English Reformation had not gone far enough. They also did not agree with some of the things the Church of England did.
King Henry VIII separated from the Roman Catholic Church in 1534 and established the Protestant Church of England. This Church remained until 1553. Queen Mary returned the Church to Roman Catholicism until 1558 when Elizabeth I of England became Queen. Since she was a Protestant many people were happy, but thought that the Church had not changed enough and was still too much like Catholicism.