Since he is literally royalty, one might expect that Prince Fabrizio would be content with his power, but because of the radically changing, evolving political environment of Europe, especially Italy and Sicily, he doesn't have that kind of confidence or comfort. It isn't like his kingdom is necessarily the largest or most powerful in the region, so during peace times, royal life must be charming and quite privileged, but with the threat of war lingering, he struggles to find peace. The novel considers power, competence, and paranoia.
When his kingdom is removed from him, he struggles to understand his identity. This is an interesting consideration, because it makes him wrestle with a serious question of honor. In his royal status, he might have taken personal solace in his power, in his role, and in his authority. So when those are taken away, where does his value as a person come from? He must consider whether he has the humility to endure the fate of a commoner. He could take a role in the new kingdom, but the impact on his pride would be irreversible.
In the end, he realizes that the blossoming love of the next generation poses a similar threat to his life. Not only is he removed from his political office; he is also being removed from the limelight of life. He is getting older, and his children are about to have children of their own. His life is coming to an end. In light of death, he realizes that his thirst for power and identity were always concealing a deeper horror; he has been kicking against his fate, but in the end, he realizes there is only one fate for mankind, no matter whether they are kings or peasants. He is only able to pray for a happy afterlife and succumb to death; the plot of his life pales in comparison to that surreal fate.
