- Sep 28, 2009
Unfortunately, no; the different religion in EU3 is almost always a dealbreaker, and you almost never see countries of different religions sign alliances.
It isn't so impossible. Just don't get into wars against them and keep searching for opportunity to make good royal marriage. In my "megacampaign"(it's not AAR). I am playing Habsburgs from CK2, now it is 1650. I've united HRE and from 1500 in Byzantium is rulling other Habsburg family. Now they are my allies, so it's not totally impossible. You just have to find good opportunity.