A quick outline.
In the mid-1520s, Henry fell in love with Ann Boleyn. She refused, however, to sleep with him outside wedlock. Desperate to have a son, and unlikely to have one with the ageing Katharine of Aragon, Henry sought a divorce with that woman to enable him to become more intimately acquainted with Ann Boleyn. He told his minister in all things, Cardinal Thomas 'Fat B*****d' Wolsey to get him an annulment. Try as he might, Wolsey just couldn't do it. Katharine's nephew Charles V had accidentally captured the Pope in 1527, and would not countenance such shame being brought to his aunt. The Pope himself didn't want trouble, and didn't tell Henry outright that 'you gotta be joking, amico'; instead, he played for time, sending over a cardinal, called Campeggio, to try the case of Rex [Henry] v Regina [Katharine] with Wolsey. Campeggio's instructions were to settle it, if at all possible, with something acceptable to Katharine, but, if not, not to give Henry his annulment. In the end, the Pope recalled the case to Rome. This was now 1529. Henry was furious, and sacked Wolsey, who went (for the first time!) up to York to spend more time with his archbishopric. (Henry then had Wolsey arrested; Wolsey, fortunately, died before Henry could kill him.)
Henry still had no divorce. His arguments, from the Bible, had failed to convince the cardinal judges, and he was stuck. Enter two clever chaps, called Thomas Cranmer and Edward Foxe. They wrote a book (known as the Collectanea) which argued that Henry, being king, was next to God and had power over the church in his kingdom, and therefore could decide on the divorce himself. They gleaned evidence from the Bible and various old laws. This made Henry overjoyed for two reasons: 1) he could get rid of Katharine and 2)it appealed to his caesaropapism.
At this point, Henry was not thinking of breaking away from Rome - as some states in the Holy Roman Empire (modern-day Germany) were. He was still a good and faithful Catholic, and was still proud of the title that the Pope bestowed on him ten years preiously - fidei defensor (defender of the faith).
Some people in England were, however, not so convinced of the Pope's necessity, or even virtue.
Reform or Reformation? The Church in 1530.
Anticlericalism: Simon Fish etc. i'm bored now. more later