Helenius Acron was considered the best of Horace’s commentators (Commentati in illum sunt Porphyrion, Modestus et Helenius Acron; Acron omnibus Melius; Vita Horati p. 3 ed. Keller 1902). All that we know of him derives from a few surviving fragments of his commentary on Terence’s comedies, and some references in Horatian scholia. Whether he commented on Terence’s entire oeuvre is unknown: Charisius preserved eleven fragments, of which eight discuss the Adelphoe, and three the Eunuchus. A further reference to Acron appears in Rufinus’ Commentarium in metra Terentiana, although it does not mention where he discussed Terence and Plautus’ metre. He probably did not write a commentary on Persius, a theory that has been encouraged by a scholium concerning the portico of Apollo on the Palatine, where Acron reported fuerint L Danaidum effigies et contra eas sub divo totidem equestres filiorum Aegypti (schol. Pers. 5.56). Since Horace refers to the Danaids in Ode 3.11, the Temple of Apollo in Ode 1.31, and the Palatine altars in the Carmen Saeculare, it is not impossible that Acron wrote this when commenting on one of these sites. He argued with Verrus Flaccus (idque Helenius Acron sic oportere dici in eadem Terentii fabula disputavit Verriumque dicit errare, qui putat hos ambo dici debere, Char. GL 1, 119.12-14), a grammarian who lived between the first century BCE and the first century CE, and he was among the sources of Porphyrion, who, in his glossary to v. 25 of Horace’s Satire 1.8, refers to Acron’s commentary for the identification of Sagana.

Since neither Gellius nor Suetonius speaks of him, and Porphyrion may possibly date around 200 CE, Helenius Acron can be securely dated between 160 and 190/200 CE.

However, it is impossible to identify the elements of the real Helenius Acron in the surviving commentaries on Horace. We have a corpus of heterogeneous glosses under his name, but they cannot be attributed to a single person or historical moment. Rather, they arise from a scholiastic stratification, the result of centuries of teaching based on Horace. The name Acron only appears, in fact, in the hand of the anonymous author of the subarchetype Z, which was noted by Pierre Daniel in a manuscript containing a commentary on Horace, and which can be dated to the end of the 14th century or, more likely, to the beginning of the 15th. [C. Longobardi; trad. C. Belanger]