Keightley edited
Virgil's
Bucolics and Georgics (1847), which was prefigured by his
Notes on the Bucolics and Georgics of Virgil with Excursus, terms of Husbandry, and a Flora Virgiliana, (1846). Other Latin classics he edited were
Horace,
Satires and Epistles (1848), Ovid,
Fasti (1848), and
Sallust,
Catilina and Jugurtha (1849). He is listed among the "distinguished file" in one survey of past commentaries on Milton, going back three centuries (). Appreciation of allusions in Milton's poems require familiarity with classical Greco-Roman mythology and epics; to borrow the words of an American contemporary
Thomas Bulfinch: "Milton abounds in .. allusions" to classical mythology, and especially "scattered profusely" throughout Milton's
Paradise Lost. Keightley was one annotator who meticulously tracked Milton's mythological sources. Some of Keightley's flawed commentary have been pointed out. He argued that Milton erred when he spoke of "Titan, Heaven's first-born," there being no single divine being named Titan, only a race of
titans. Though that may be so according to the genealogy laid out by
Hesiod's
Theogony, it has been pointed out that Milton could well have used alternate sources, such as
Lactantius's
Divinae Institutiones ("Divine Institutes"), which quotes
Ennius to the effect that
Uranus had two sons, Titan and
Saturn. Likewise regarding Milton's
angelology, Keightley had made some correct observations, but he had constrained the source mostly to the Bible, and made mistakes, such as to identify the angel
Ithuriel as a coinage.
Other commentary Keightley also published an unannotated edition of Shakespeare (6 vols. 1864), followed by a study guide entitled ''Shakespeare Expositor: an aid to the perfect understanding of Shakespeare's plays'' (1867). He also wrote of
Henry Fielding's peculiarism of using the antiquated "hath" and "doth" ( ''
Fraser's Magazine'', 1858), without acknowledging a commentator who made the same observation before him. ==Friends and family==