Love Sacrifice (1976)

Leonidas, of noble lineage but poor, serves in the house of Count Aristide Of the Fava Dongo, waiting patiently for his death to arrive. He dies at last, but rumors reveal that, on his deathbed, the Count has decided to leave everything to Marco (Claudio Ercoli), his illegitimate and retarded son who secretly grew up in a boarding school. In the meantime, the whole family of Leonida moves to the luxurious estate as for certainly no one wants to miss out on this wealth opportunity...