Because Henry wanted to have a son but couldn't with every one of his different wives, he had went against his religious valves. When he did, he had changed England in a certain way. He had made people turn against the pope, so that way Henry could have the authority to be in charge of the churches, so that way it can allow him to get a divorce and try to find a woman who is young, so he could try to have a son. Once Henry died, all three of this children had each a turn of becoming ruler of England. Things didn't go according to plan as Henry had hoped.
Hope this helps!:)
