Mission Impossible?

[parashar91]

I'm playing as Spain with Missions Expanded and its 1544. The mission "Habsburg Succession" requires the following:

1)Ruler must be von Habsburg
2)Austria's ruler must also be Habsburg
3)Relations of 200
4)Spy Network of 50
5)Royal marriage
6)Austria must not have an heir

Now I understand that for my Spain to have a Habsburg ruler I need to have a Royal Marriage with Austria; but then isn't it all a matter of luck and chance that I get a Habsburg ruler through the marriage?
Also, how on earth do I ensure that Austria is without an heir after all this? Everything else I can manage.

 

[Kanem Bornu]

You can disinherit your heirs and also make sure they're leading armies into battle to increase their death risk. As for their heir, not a lot you can do to control it other than to pull them into a lot of wars and hope they also put their heirs in charge of armies.