DIANIRA, DIANIRE, DIANYRE, DYANIRA. Dejanira was the daughter of Oeneus of Calydon and Meleager's sister. Hercules won her in a contest against her other suitor, Achelous, a shape-shifter. As he took her home to Trachis, he came to the river Evenus, then in full flood. He paid the centaur Nessus a fee to carry Dejanira across. The centaur, however, ran off in the opposite direction when he reached the bank, intending to rape Dejanira. Hercules slew him with the shot of one arrow, which had been dipped in the poisoned blood of the Lernean Hydra. As he lay dying, Nessus told Dejanira to collect some of his blood; if she dyed Hercules's shirts with it, the shirts would become love charms to help her regain his love if she ever needed to. Later, when Hercules brought Iole to live with Dejanira, she sent him a shirt when he stopped at Cenaeum to offer sacrifice to Jupiter. The poison consumed his flesh, and he tore off his skin when he tried to remove it (Heroides IX; Met IX.1-272; OM IX.1-872). The story also appears in Boccaccio, De claris mulieribus, XXI and XXII. The Jealous Husband tells that Hercules overcame twelve dreadful monsters but was overcome when Dejanira sent him the poisoned shirt, RR 9195-9200. Gower tells the story of Hercules, Dejanira, and Nessus to illustrate Falssemblant, Confessio Amantis II.2145-2319; Machaut's version is Le Confort d'ami, 2683-2762.

The Man of Law says that Chaucer has told the "pleinte" of Dianire in a large book, MLI 60-66, but there is no story for her in The Legend of Good Women. Jankyn reads the story to Dame Alys from his "Book of Wikked Wyves," WBP 724-726. The Monk tells the story as part of the Hercules legend, MkT 2120-2134. Hercules is false to Dyanira when he brings home Iole, HF I.402-404. [Achaleous: Ercules: Nessus: Yole]

Dianire, with elided final -e, occurs medially, MLI 66; Dianyre, with silent final -e, occurs finally, WBP 725; Dianira, in medial position with four syllables for the meter, MkT 2120. Dyanira occurs in final rhyming position, HF I.402. All variants are developments of Latin Deianira.