Wikipedia
Hilarius (poet)
Hilarius ( fl. 1125) was a Latin poet who is supposed to have been an Englishman.
Hilarius (praefectus urbi)
Hilarius (floruit 408) was a politician of the Western Roman Empire.
Hilarius is known to be the praefectus urbi of Rome in 408. He is attested in office on January 15 of that year by a law preserved in the Codex Theodosianus. He has been sometimes identified with a Hilarius Praetorian prefect of Gaul in 396, but this identification is rejected by historians on the fact that the urban prefecture was a lesser office than the praetorian one.