With Plutarch, who dedicated to him his treatise IIEpi Tov irpwrov 11vxpov, with Herodes Atticus, to whom he bequeathed his library at Rome, with Demetrius the Cynic, Cornelius Fronto, Aulus Gellius, and with Hadrian himself, he lived on intimate terms; his great rival, whom he violently attacked in his later years, was Polemon of Smyrna.
However praiseworthy the intention may have been, the list of authors specially recommended does not speak well for Fronto's literary taste.
Till 1815 the only extant works ascribed (erroneously) to Fronto were two grammatical treatises, De nominum verborumque diferentiis and Exempla elocutionum (the last being really by Arusianus Messius).
In that year, however, Angelo Mai discovered in the Ambrosian library at Milan a palimpsest manuscript (and, later, some additional sheets of it in the Vatican), on which had been originally written some of Fronto's letters to his royal pupils and their replies.
The letters consist of correspondence with Antoninus Pius, Marcus Aurelius and Lucius Verus, in which the character of Fronto's pupils appears in a very favourable light, especially in the affection they both seem to have retained for their old master; and letters to friends, chiefly letters of recommendation.