Back on the Roi Soleil after years of not posting to this thread. In this post, I will explore some of the big what ifs and conspiracy theories of his life. For someone whose youth was so filled with action, that he lends himself well to such discussions.
Was he the son of Louis XIII?
One of the big themes we see, particularly in modern-day movies is that Louis the XIV may not be Louis XIII's son. A number of movies leave this thread hanging or making the paternity one of the threads they either explore or leave hanging. With Louis being the son of a variety of people: from Richelieu, to the Duke of Buckingham, to one of the Three Musketeers (Athos or D'Artagnan usually) to a chamber servant.
That his mother Anne of Austria and his father not have the most loving relationship, they may have become friends, but I don't think they really loved each other: a dynastic marriage indeed. With that said, as a Spanish Princess (yes, I always thought it was hilarious that Anne of Austria was from Spain), she must have understood her role was to bear the king and heir above all. If she were caught doing something inappropriate - such as sleeping with another man - she would have been slandered and the king's legitimacy been questioned during the days of the Fronde.
However, while the Queen-Mother was slandered later, it was for her affair with Mazarini, which started after her husband's death. Many of these attacks were vicious and merciless. But I do not recall reading any doubts about the King's paternity. So I have to think that it was not something which was discussed at the time.
His father Louis XIII was heavily suspected of being a homosexual or at least bisexual as he was not known to have had any mistresses and no illegitimate children outside his marriage. I think that if his wife "suddenly" became pregnant he might have said something, but he did not.
So I think it is fair to assume that Louis XIII is the most likely father of the Sun King.
However, for game purpose... this is very good: we have a famous person and a reasonable conspiracy. The PCs could approach this from a number of ways: they could try to unmask the one responsible, one of them could have a thing for Anne (...), they could later seek to cover up tracks and clean up loose ends (as a very Mazarini thing to do).
What would've happened to him if the Frondeurs had taken him in custody?
Although the Frondeurs did get hold of young Louis, they squabbled away their military advantage in the political court. Mazarini managed to outplay them all and got them to fight amongst themselves. But what would have happened if the Conde managed to hold things together and not break up their party? This is one of the greatest defeat for a victory. The Princes won the war but eventually lost their power in favor of the king.
A lot of "what if"...
What if Mazarini had given up and accepted exile?
What if, following his early defeats, the cardinal had stayed away from France? This brings us to a number of interesting scenarios.
First, like in England a century and a half later, there remained an uncle (Gaston d'Orleans), a young king and his brother (Louis and Monsieur). Could we have seen the story depicted in Shakespeare's Richard III played out again? His descendents would, later (under the 1830 revolution) become kings.
Second what if the Princes of Conde had seized power for himself, he did have a claim to the throne and enough military prestige to ensure his victory. Mazarini's unpopularity helped. In the end, he got played, and Mazarini returned from Germany with a mercenary army.
What would Louis have learned from the Cardinal's defection?
The Man in the Iron Mask?
The most enduring myth surrounds the man in the iron mask. A prisoner whose head was locked in an iron mask. The French Revolution destroyed a lot of the records, but the story is persistent enough that there is likely something there.
From a campaign perspective, two reasons for his imprisonment include:
1 - He is Louis's twin brother.
2 - He knows something about Louis's birth that requires him to be removed from circulation but not killed for it.
Both of the above definitely provide material for a campaign. Alexandre Dumas's Le Vicomte de Bragelonne provides us with one particular possible outcome.