The subject of the present picture is taken from Ovid's Metamorphoses (9: 101-133). On their way from Calydon, Hercules and his wife Deianeira came to a river where the Centaur Nessus was the ferryman. Having overcome Hercules first, Nessus attempted to ravish his wife, whereupon the warrior drew his bow and slew the ferryman with an arrow poisoned with the hydra's gall. As Nessus lay dying, he gave Deianeira a drug mixed with the blood from his wound and told her it was a love-potion. When later she tried to re-awaken Hercules' love after he had fallen in love with Iole, she sent him a shirt soaked in this potion which corroded his skin until he could stand the agony no longer and sought death on a funeral pyre.