Another thing I have been wondering is what if Charles II's issue of 1662, 1666, 1668 and 1669 had all survived with two being boys two being girls. If we go by this:
1662: Princess Henrietta
1666: Princes Charles
1668: Princess Anne
1669: James
What might this have changed in regards to dynastic politics of the 17th century england, and would this have allowed for a thing such as the glorious revolution to occur or not?