Introducing Constantine II of Hungary

"King Constantine." You don't need to name him any more than that; everybody will know who he is, just as well as they'd recognize "Count Dracula." And for the same reasons.

The guy is hated across cultures.

Let's introduce him...

Biography

Constantine II of Hungary is born sometime in the late 1460s, in time to see the fall of Constantinople in 1476.

• Before Constantinople's fall, the last king [who?] arranges for his kids [who?] to be married off. Constantine is set up with an illegitimate Hungarian princess [who?], on the understanding that she'll convert to Orthodoxy on the marriage.
• In 1492, when they finally marry, Constantine's wife doesn't convert. He converts to Catholicism instead for political reasons, beginning a long and troubled religious life.
• Constantine II has a healthy sex life: a huge number of daughters [who?] with his wife, as well as a few children with various others. One of the bastards is acknowledged as a son, and carries on his name.
• In 1524, Constantine does not get killed by the Turks, who do not overrun Hungary as a result. (The exact consequences this has on history remain to be discussed.)
• Constantine dies under mysterious circumstances, without benefit of extreme unction.

The Curse of Constantine

• As of 1930, no man alive can trace his family origins back to the lawful union of Constantine II and his wife. For whatever reason, all of them are daughters.
• Because Constantine II did have sons, nobody initially thought much of it. Those daughters, therefore, wound up marrying around to some interesting people, whose male-line extinctions a generation later really helped to plunge Europe into chaos. This indirectly helped fuel the apocalypse that was the Hanseatic Wars, and directly triggered the French Wars of Religion.
• At some point in the future of Andalusada, genetic therapy will break the Curse of Constantine, and a son will be born to him.

King Constantine II in culture

Because of his tsundere relationship with Rome, and his mysterious death, folklore quickly declared that Constantine II was doomed to walk the world until Judgment Day. By 1930, his legend has spiraled into a quintessential part of the vampire mythos.

• His tsundere relationship with Rome also set in motion the rise of the Uniate* churches later on, who generally regard him somewhat amicably (the way Protestants IRL think about the Hussites.)
• Constantine II is the Central European equivalent of Henry VIII. Most significantly, the drama caused by the Curse directly leads to the establishment of the Church of Hungary.

Points of Divergence
Part of what makes Constantine II an interesting character (for me, at least) is because lots of divergence points tie directly into his life. His dynasty is Central Europe's answer to the Tudors: big names at critical moments.

• If in 1492 Constantine II didn't convert to Catholicism, he very likely wouldn't have become King of Hungary at all. Whether Hungary would have fallen to the Turks is up for discussion; I have no idea who his rivals were, or how competent they were in war. One side effect of this is that as a noble has-been he would've been much less marriageable, and the Curse of Constantine, while probably doing interesting things to the Magyar political landscape, would never have caused the chaos it did.
• If Constantine II had divorced his wife (as he apparently thought of doing at some point), he probably would have had to convert. This probably would also significantly abet the Curse, but it would have caused a much more complex religious landscape to deal with.
• Slight changes in European marital politics could have totally resculpted the landscape of Europe in the next century, with or without the Curse.