Scafoglio gives an overview on the ‘Hercules-theme’ in Dante Alighieri’s thoughts and poetry, paying special, but not exclusive, attention to The Divine Comedy.
Dante explicitly mentions his sources in the Convivio as Ovid, Lucan and ‘other poets’, among whom Virgil must number and treats specific incidents from Hercules’ life, e.g. Hercules’ killing of the Lernean Hydra (Epistle 7), where the hero becomes a model of virtue and strength, an example to emulate, for addressee, Emperor Henry VII, with the divine origin of Hercules providing feedback on the divine origin of imperial power (as asserted by Dante in the treaty De monarchia).
In The Divine Comedy, two short references to Hercules’ death due to Nessus’ posthumous revenge (Inf. 12.67-69) and Hercules’ love for Iole (Par. 9.101-102) seem to be no more than cultural allusions, aimed demonstrating mythological erudition. It is significant, however, that Dante does not express a moral judgment on Hercules’ love for Iole, remains silent on adultery and does not refer to lust; instead, he points to this love as a (positive) example of a strong and deep feeling.
On the other hand, the references to the capture of Cerberus (Inf. 9.98-99) and the killing of Cacus (Inf. 25.25-33) are far more important to the moral background of the poem, since Hercules is viewed as the champion of Good defeating Evil. Although Dante shows this more frequently through Hercules’ fight against the giant Antaeus (Inf. 31.112ff. and in particular 132; but cf. Conv. 3.3.7-8; De mon. 2.7.10 and 2.9.11). Thus, in Dantes’ thought and especially in The Divine Comedy, the Hercules-figure is a symbol of Good in the eternal struggle against Evil, although the hero is not an allegorical pre-figuration of Christ (as he is already in some Medieval texts, and will be, increasingly, in the Renaissance).
Finally, Dante’s Hercules works as a trait d’union, a connecting and mediating figure, between the hero of flesh and blood of classical antiquity (sometimes already interpreted as champion of Good, e.g. in the Aeneid) and the symbol of Christ, as he will become in the late Middle Ages and Renaissance.