Can I create or usuper other Imperial titles ?

[BaronNoir]

(I'm the Emperor of Britannia ATM, and I hold much of the Byzantine empire lands...)

 

[brucepm]

Yes. You'll need to hold at least 80% of the relevant title's de jure land, though, so it's not easy. Once you have it, it'll operate just like a king with multiple king titles-- one is your primary title, and each has its own individual succession laws that you'll have to pay attention to if you want the same person to inherit them.

 

[Hackworthy]

It's not really worth it to hold multiple Imperial titles, it rather defeats the very nature of an Empire.

 

[Gheald]

until the de-jure drift of kingdoms within empires is fixed than it is worth having multiple empires.. as your CA of your empire only affects de-jure kingdoms.

Found this out recently after creating brittania and raising my CA to absolute.. only wales, ireland, england and scotland are subject to the CA.. my spanish vassals still constantly fight each other and the empire of hispania does not exist.