In which Targaryens are featured? Game of Thrones?

In addition to Daenerys and Viserys, Aemon Targaryen (Peter Vaughan() was used throughout the series. Known as the last known Targaryen in Westeros, he was the great-uncle of Daenerys and Viserys. 

It is revealed in the finale of season seven that Jon Snow (Kit Harington) father is Rhaegar Targaryen (Wilf Scolding) and that his birth name is Aegon VII Targaryen, making him the heir to the Iron Throne and Daenerys’ cousin. 

Why is House Targaryen so intricately intertwined with the family tree?

Simply put, they loved to wed.

Based on Game of ThronesThe family was known for marrying multiple siblings to preserve the bloodline. 

Inbreeding can sometimes lead to genetic problems. “Madness and greatness are two sides of the same coin,” Lord Varys (Conleth HillThe Targaryens of season 8 were mentioned by. The gods throw the coin into the air every time a Targaryen is born and everyone waits for the result.