The answer to this question depends on which version of the story you are referring to.
Celaena Sardothien in Throne of Glass
In the Throne of Glass series by Sarah J. Maas, the king, King Dorian of Adarlan, does not know Celaena's true identity as the assassin, Celaena Sardothien. However, he does know that she is a skilled assassin, and he is impressed by her abilities. He even offers her a position as his personal assassin.
- Celaena's Identity is a Secret: Celaena adopts the alias of "Celaena Sardothien" when she enters the King's Selection. Her true identity as the assassin, "Aelin Galathynius," is kept secret throughout most of the series.
- King Dorian's Perception: King Dorian is initially unaware of Celaena's true identity. He only knows her as the skilled assassin who entered the King's Selection.
Celaena in Other Works
If you are referring to a different story or adaptation, the answer may be different.
For example, in the television adaptation of Throne of Glass, the King might be portrayed differently and his knowledge of Celaena's true identity could be altered.
To provide a more accurate answer, please specify which version of the story you are referring to.
