Starting to see a pattern, so far i'm starting to think alicia is following the novel.
If in the novel alicia meets the ML before the ML meets the other princess (miss what's her face), it's entirely possible she did have a relationship with the ML, and died because of unknown reasons, this would explain him turning on the emperor (in case he either had something to do with it, or let it happen through negligence), it would explain why lancelot leaves him, and it would explain how he ended up with ms prissy pants.
Alicia better watch princess prissy pants, i think she might try to "get rid of the competition" if you get my drift.