I have heard that King James abdicated in favour of Reinhardt. James has taken the title of 'Marshall', which implies he still runs things and Reinhardt is just a figure head- just like I was till I retired my emperorhood. I think it's called 're-branding'.
As anyone who is a fan of history knows, the title of 'Holy Roman Emperor' could be claimed by anyone. In order for it to stick, you actually needed an empire, but still you could claim it in hope someday you would. Little things like the Professor and his Reformation would throw things off, but a good politician could always reinvent it for his own needs.
I myself, after serving as a figurehead, had to give it up. When my mighty warriors turned into surrender monkeys (a fine bit of mercenary attitude; they prospered for it and I admire them for that), I had no strength to enforce my will. I became a figure head, and it was fun for a bit, but then it got old. My commands became requests, and they were mostly denied. The last army given to me to support my endeavors was Rodrick aka Goblin King aka Viscount aka Saturn. And you can guess how well that went.
That was disappointing, but when the uber wealthy south did not help us defend Curaw, the soul of the HCE, the birthplace of the HCE and spiritual headquarters of Acre, well then I realized the Empire was dead.
But, like the HRE, the HCE can disappear and reappear. Does the HCE have an emperor? Or is the 'empire' just the old kingdom who lost interest in ruling the world?