In the book The Exodus, the island of Olenveld is said to have been Tiber Septim very own personal graveyard, with gravestones dotting all over the settlement. But, what does "personal graveyard" means in this context? It's a hidden place to bury the emperor's many many enemies? If that's so, why not just burn the bodies or throw them in the sea? It's a grave to his own men who died in battle? Could they not be send to their homelands where the local customs would be respected?
I know there's not much lore to this settlement, just one book that might be just fiction and a CC content (which is of dubious Canon). Nevertheless, I want to hear your headcanons and possible explanations to why Tiber Septim would have a personal graveyard in a cold, distant and forgotten island and whoever is buried there.