1976’s Lady of the Bees is the third book in Thomas Burnett Swann’s Latium trilogy. It is a mythological fantasy about the founding of Rome.
In this age supernatural beings are increasingly rare, pushed aside by mundane humans. Mellonia, former queen of the dryads, avoids humans and lives in solitude deep in the forest. She has had human lovers in the past — Aeneas and later his son Ascanius — but now she avoids concerning herself with human affairs.
She breaks this policy when, on a whim, she rescues infant brothers, human twins. Her choice shapes human history for millennia to come.