Why did Henry VIII break from the Roman Catholic Church?

First of all Henry VIII wanted a son to continue his line and create a dynasty. He previously had only had one daughter (Princess Mary) to his now old wife Catherine of Aragon. As she was past child bearing age and he had fallen in love with a daughter of one of his Ambassadors (Anne Boleyn), he seeked to have the marriage dissolved in order to marry Anne and potentially have a son. He first asked his chief minister Wolsey to seek a dispensation from the Pope for an annulment of the marriage, based on the fact Catherine was previously married to Henry's elder brother Arthur before he died, and this went against the holy book of Leviticus. However, Wolsey was unable to get this, firstly due to his lack of negotaiting skills, but secondly because the Pope had become a prisoner of Philip of Spain in the Italian wars (who was Catherine of Aragon's nephew) making it almost impossible. 

In the mean time, Anne Boleyn (due to her time at the French court) had become a Lutheranist, and waved many texts and books under Henry's nose that ultimately made him turn against the Pope. Henry believed that because he was anointed by God, whatever he wanted, God must want. Therefore he got an act passed by parliament that announced him as the Head of the Church of England, turning England into a Protestant country and allowing Henry to marry Anne.