There is a passage in the Augustan History, p. 137, in which Lampridius, whilst he praises Alexander Severus and Constantine for restraining the tyranny of the eunuchs, deplores the mischiefs which they occasioned in other reigns.
Huc accedit, quod eunuchos nec in consiliis nec in
ministeriis habuit; qui soli principes perdunt, dum eos more
gentium aut regum Persarum volunt vivere; qui a populo etiam
amicissimum semovent; qui internuntii sunt, aliud quam
respondetur [saepe], referentes; claudentes principem suum,
et agentes ante omnia ne quid sciat. [Lampr. Alex. Sev. c.
66.]