Simplify the following text for a Grade 9 native English-speaking person.
Original: He was one of the strongest advocates of the English Reformation , the English Church 's break with the papacy in Rome , and helped engineer the King 's divorce from Catherine of Aragon in order to marry his mistress Anne Boleyn .
Simplified: He was one of the strongest supporters of the English Reformation , the English Church 's break with the papacy in Rome .