He is known for the words he wrote for Handel's oratorios Esther (1732), Deborah (1733), and Athalia (1733).
Humphreys was an educated man, who wrote as a poet from around 1728 to 1732, a period during which he also worked for George Frideric Handel.
He wrote also:[1] For Handel, Humphreys provided expansion to the libretto for Esther (1732), and the libretti for Deborah (1733), and Athalia.
Besides writing original libretti, he translated the following dramas and operas: Poro, Re dell' Indie, 1731; Rinaldo, 1731; Venceslao, 1731; Catone in Utica, 1732; Ezio, 1732; Sosarme Re di Media, 1732.
His Peruvian Tales (1734, republished in 1817), translated from Thomas-Simon Gueullette, and continued by Samuel Kelly, were popular.