There seems to be a lot of madness going around. Which I personally enjoy a lot right now.
In my new ironman (currently year 808, House Mojmírid Kingdom of Great Moravia) I have had one king get eaten by Cthulhu. Another lost an eye in a drunken fight, turned crazy and possessed, got the Great Pox, sacrifice an arm to his ancestors to cure in order to cure his pox (which worked), sired a healthy heir, weaved an intricate web of alliances with Slavic pagan tribals in order to strike at the Avars before finally getting poisoned by his brother who turned independent taking half the kingdom with him, without even seeing his dream of crushing the Avars come to fruition. That guy was avenged by his uncle who got the kingdom (tribal elective) and reclaimed the lost half of the realm. The avenging King Rostislav the First reigned for a record breaking 12 glorious years before dying in his sleep, only to be succeed by his leaper son who lasted for less than a year. My current king has recently bought the Necronomicon, which will go down well I am sure.
Also Charlemagne died of cancer at age 30, Karloman's son inherited the realm but King Pepin died of the Flu at age 14. Leaving the realm to King Grifo the Usurper king of Bavaria who also died of Cancer, the Frankish realm was split between his sons, before being reunited under his Grandson Teutbald who is currently successfully fending off a Iberian Muslim invasion.
Saxony turned Sunni and as a result a number of now ex-Slavic realms has embraced their faith via missionaries. Saxony constantly wages Jihads against the Frankish realm but so far have not been successful, so they spend their time raiding Frankish border counties.
Byzantium is doing well, they have actually managed to spread their Orthodox faith to the Kingdoms of Croatia-Serbia and Bulgaria without holy war resulting in peace in the Balkans.
Avaria is still Tengri but a number of Lords have converted to either Sunni or Orthodox, so its only a matter of time before they flip to either.
At this point Great Moravia is a third Orthodox, a third Slavic and a third Sunni. Ruled by a Slavic zealot squised in between a Slavic Polish kingdom to the North, a united Catholic Karling realm to the west, indecisive Avars to the south and Stronk Orthodox Byzantines and Croatian/Serbians to the south east.
So yeah lots of madness and death in this grimdark medieval past. I love it.