So, WI Queen Catherine of Braganza, Charles II's wife, had managed to carry a child to full term and produce a healthy son? Obviously the history of England would have been greatly altered, as we wouldn't see a Glorious Revolution, which means we won't get a Bill of Rights anytime soon.
The power of the Crown would also probably be strengthened, especially if Charles dissolves his Parliament and rules with out them for a number of years as he does in OT.
I'm thinking that England may end up like Sweden during the seventeenth century, with an absolutist monarch after all (and with the horrors of the Civil War fresh in everyone's mind, who is to stop it?).
Then there's the alliance with France to consider and its implications...
What does everyone think? I'd love a discussion...