Given the Fae Race's long lifespan and their keen information network.
Gaven had previously mentioned the Tree Spirit Kingdom to Lord Virginia as a tentative probe, and unexpectedly, she indeed had heard about it. However, her knowledge was relatively limited, knowing only that this kingdom's history was extremely ancient, far predating the Komeer Kingdom.
In their eyes, they are the true owners of that land, while the Komeer Kingdom is seen as an invasive force.
This is the classic cause of conflict between the Fae Race and the Human Kingdoms, and such conflicts often prove hard to reconcile.
Because of this, Gaven could already foresee the difficulty of his current mission. Both sides regard this land as their home and will undoubtedly stand firm without compromise. Moreover, the berserk beast disaster he caused in the King's Forest has already lowered his favorability in the eyes of the opposition.