I suggest that you read up a bit on the history. There is a mnemonic about the fates of Henry VI's wives: "Divorced, beheaded, died. Divorced, beheaded, survived." Henry VIII beheaded two of his wives, Anne Boleyn (on trumped-up charges) and Catherine Howard (on quite legitimate charges -- adultery by the queen was treason under the statute). Of the others, two were divorced (one for non-consumation), one died in childbirth and the sixth outlived him.

Henry actually had solid grounds for an annulment. His father, Henry VII, arranged a marriage between his eldest son, Arthur, and Catherine of Aragon. A few months afterwards, Arthur died. The king wanted to keep the Catherine's dowry (over a million in today's currency, which would have had to be repaid out of the Privy Purse). So he decided to marry his second son, Henry, to Catherine. There was a problem: Under Church marriage law, one cannot marry one's deceased spouse's sibling.