Question

why did henry viii break with the roman catholic church ?

Answer 1

In short, he wanted to annul his marriage (Henry was desperate for a male heir, but his wife didn't give him one, so he wanted to marry someone else) but the Church refused to give him a divorce.

After a large degree of political jousting and debate, he eventually got his divorce by divorcing the Church in England from the rest of the Roman Catholic Church. Oh, and that also made the king of England its spiritual leader. Convenient, no?

There are a number of other reasons that contributed to the break, but this is the one that stands out in most people's minds.