I started out my game as emperor Romulus, and actually managed to make him a brilliant strategist of a ruler, and I sired multiple children to the throne. Apart from being forced to maintain gavelkind, I wasn't threatened at all, and I began to slowly reconquer western rome. I took the Vandalic Islands and half of Burgundy, quickly taking what was directly, and de jure, part of the Western Roman empire.

Even after I died, I ruled as my son, Paulinus, for 8 years before he died of severe stress, and as his daughter, I ruled until I committed suicide at the age of 88 after becoming infirm. Even than, I had made several reconquests against former roman lands, and by that point almost all of gaul and all of italia, and even a large chunk of Hispania was under my rule.

My heir, thanks to some claim pressing I had made decades before, was my grandson. The basileus of the Eastern Roman empire. So, when I finally died, Both the western and eastern halves of the empire belonged to me.

There was... just a small problem.

My threat level is high, that might play a part... but the imperial reconquest casus beli is gone, and it's the year 612. I can't declare them for either half of the empire.

Why?