The knight and chamberlain are very sus. An oath breaking knight should not be trusted. The old man looks like a cliche evil vizier, might be a red herring as it's a little too obvious.
I think that's at least the third princess or queen named Satia that I've come across in Japanese fiction. One was in an as-yet untranslated LN called 女神なんてお断りですっ。, but I don't remember where the other was... I just remember seeing it and thinking "hey, another one!"