The Metamorphoses of Ovid, Books VIII-XV

Latinus having been told by an oracle that a foreign prince should come into his country and marry his daughter Lavinia, received Æneas hospitably, and formed an alliance with him, promising him his daughter in marriage; on which Turnus, who was the nephew of Amata, his wife, and to whom Lavinia was betrothed, declared war against Æneas.

The ancient historians tell us, that, on returning from the siege of Troy, Diomedes found that his throne had been usurped by Cyllabarus, who had married his wife Ægiale. Not having sufficient forces to dispossess the intruder, he sought a retreat in Italy, where he built the city of Argyripa, or Argos Hippium. Diomedes having married the daughter of Daunus, quarrelled with his father-in-law, and was killed in fight; on which his companions fled to an adjacent island, which, from his name, was called Diomedea. It was afterwards reported, that on their flight they were changed into birds, and that Venus inflicted this punishment, in consequence of Diomedes having wounded her at the siege of Troy. Of this story a confused version is here presented by Ovid, who makes the transformation to take place in the lifetime of Diomedes. It is supposed that the fact of the island being the favourite resort of swans and herons, facilitated this story of their transformation. Pliny and Solinus add to this marvellous account by stating, that these birds fawned upon all Greeks who entered the island, and fled from the people of all other nations. Ovid says that the birds resembled swans, while other writers thought them to be herons, storks, or falcons.