User blog comment:The Dragon Demands/The History of House Targaryen. Part IV: The Dance of the Dragons/@comment-1164470-20131103111402/@comment-1164470-20131103190609

Prince Aemon seems to have been Rhaenys's father, so... In 92 Baelon was chosen to be Jaehaerys's heir (if what I read is right, that's in this context that his name was spoken) when Jaehaerys started to manage his own succession. So if Baelon was Jaehaerys's first born, this has no sense... After this, there is a great council in 101 in wich Viserys became Jaehaerys's heir instead of Rhaenys (the queen that wasn't)... Son Baelon died in 101. Or maybe 100. If he was Rhaenys's first husband, she remarried the Velaryon guy only after that. So Laenor and Laena are born post 100. The Danse begins  in 129 and Laenor/Rhaenyra's got 3 children ; it matches with dates.

But : If Rhaenys was just Viserys's mother there is still no problem at all. Same line and a women never owned the throne so the crown should have been to Viserys without a Great Council was usefull.

I believe it is the opposite. Aemon was the elder son and Baelon was the younger. Baelon married his niece (Aemon's daughter). With her he has Viserys and  über-Daemon.

Then in 92, Aemon dies. First succession problem. The kingdom has a choice between Rhaenys (Aemon's only daughter) and Baelon. The North supports Rhaenys (because like it is said in ADWD, in the North a girl comes before her uncle) but Baelon is chosen, more direct ancestor, but a cadet.

In 101, Baelon dies. Second succession problem. Rhaenys's rights are again bypassed to her son Viserys ; a male and reunion of the elder line (form Aemon) and cadet line (from Baelon) and Rhaenys remarried the Velaryon guy.

Is it possible or is it totaly 100% sure that Baelon was Jaehaerys's elder son ?

PS: I tried a speculative family tree attempt with this informations Is you see any impossibility, let me know : http://www.lagardedenuit.com/wiki/index.php?title=Maison_Targaryen_%28g%C3%A9n%C3%A9alogie_test%29

Thanks a lot :)