Board Thread:TV Show Discussion/@comment-1399600-20170609041431/@comment-27751431-20170906124440

Mattman15 wrote: The point of Dragonstone is to protect the heir until their ascension to the Throne thus the title "Prince/Princess".

When Stannis took the castle he was Lord of Dragonstone because he wasnt the heir.

With no heirs to the throne and Daenerys be the only Targaryen her title is Lady as she is not and heir.

Techinically speaking, Stannis was actually the heir , until Joffery was born.