Albrecht VI von Habsburg
Albrecht VI was basically a dumb guy who cared only for his own pleasures. It should not come as a surprise that once he took over the throne from his late father it the whole empire basically went downhill. Not territorially speaking, as the Bavarian Empire was way too big and powerful to be eaten by it's jealous though toothless neighbors. No, it was a combination of inside and outside influences.
Still, it wasn't all bad. Albrecht luckily had a few excellent advisors around who tried to contain the damage. They started with diplomatic overtures to Dauphiné, as it had provinces that rightfully belonged to Bavaria, but was also a vassal.
The previous emperor didn't leave the country in the best of conditions either. He had not taken full advantage of the opportunities offered by the discovery of all the strange new worlds out there. He had started colonization in the Far East, on some small islands, but hadn't really put his heart in it. That would have to be mended in the future.
The summer of 1760 was an excellent. Not necessarily for the farmers, who found it too dry and too hot, but for the emperor it was great. He also got so hotheaded he invaded and conquered the independent island Gotland because, and I quote: "I felt like it." What can one do then, being this emperor's advisor? It's hopeless, right?
This of course didn't go well with not only the Bavarian populace, but much more so with the foreign courts. The infamy of the Bavarian nation grew and grew, until we were finally seen as being "the spawn of the devil".
Several nations foolishly went to war with us over this, but of course they could not do anything against our superior armies. All attempts to humiliate us were thwarted, though the advisors managed to convince Albert VI that taking more territories from them would not be wise.
Meanwhile Albrecht had gotten it into his head that he did not want to be the Absolute Monarch of bavaria, but instead wanted to rule like an Enlightened Despot, as he felt certain he knew what was best for all his citizens.
His vassals had other thoughts about this. In a fit of rage he revoked the privilegia of those of his vassals that were part of the Holy Roman Empire. Not much remained independence remained for the once self-serving princes of the Empire.
After less then 20 years on the throne finally Albrecht VI died, leaving behind a country plagued by rebellions and less efficient then it was when he started his reign.