Final answer:
Henry VIII initiated the Reformation in England by breaking from the Roman Catholic Church to establish the Church of England, after the Pope refused to annul his marriage to Catherine of Aragon.
Step-by-step explanation:
The individual who started the Reformation in England was Henry VIII. Unlike reformers such as Martin Luther and John Calvin, who were true believers in the doctrines they espoused, the English Reformation had a different character. It was imposed from the top down, primarily by a king looking for a way to annul his marriage and remarry in hopes of securing a male heir.
Henry VIII's request for an annulment from Catherine of Aragon was initially denied by Pope Clement VII, leading to a significant break with the Catholic Church. Ultimately, Archbishop Thomas Cranmer granted the annulment, and this act, along with subsequent legislation passed through Parliament under Henry's direction, catalyzed the English Reformation, severing hierarchical ties with the Roman Catholic Church and establishing the Church of England with the monarch as its supreme head.