In ASOS Chapter 6, Olenna Tyrell says this to Sansa Stark:
You Starks were kings once, the Arryns and the Lannisters as well, and even the Baratheons through the female line, but the Tyrells were no more than stewards until Aegon the Dragon came along and cooked the rightful King of the Reach on the Field of Fire.
Baratheons are descended from two Royal Dynasties through females:
- House Durrandon through Princess Argella of Stormlands
- House Targaryen through Princess Rhaelle Targaryen
Which female line is she talking about here? The Targaryen female line or the Durrandon female line? Or is she talking about both?
Since Princess Argella was heir of her father and shortly ruled as Storm Queen before her defeat, I am more inclinded to believe Olenna is talking about Baratheons being heirs of House Durrandon through Argella, who ruled Stormlands for centuries in their own right before the Dragons came. The context also makes me think that way because she was talking about Royalties of Pre-conquest era.