I see a lot of people did the work and are missing the badge . It might be interesting to collate and see if one of the workouts was faulty . <| sep |> It had long been the custom amongst the dragonlords of Valyria to wed brother to sister , to keep the bloodlines pure , but Aegon took both his sisters to bride . By tradition , he was expected to wed only his older sister , Visenya the inclusion of Rhaenys as a second wife was unusual , though not without precedent . It was said by some that Aegon wed Visenya out of duty and Rhaenys out of desireTWOIAF Basically the Targaryens traditionally practiced incest whereas polygamy was unusual , so when they realised that the faith and the seven kingdoms would only tolerate one or the other they picked incest .