Pisidice's infatuation with him was so great that she willingly betrayed her home city for his sake on the promise Achilles would marry her, but after conquering Methymna the hero put her to death for treason.
Her story has many shared elements with other heroines who betrayed their besieged fatherlands after falling in love with the enemy, only for their supposed lovers to punish them accordingly for treachery, while at the same time reaping the benefits of the women's treason.
[15] Pisidice's treason and subsequent death sentence was a subject of the Hellenistic poem The Founding of Lesbos, which Parthenius of Nicaea quoted and used as a source in his work Love Romances.
[17] Apollonius drew heavily from the older Homeric, Hesiodic and cyclic traditions for the writing of the Founding of Lesbos, particularly the motif of a young girl who betrays her land out of love for the conqueror.
[16][18] Moreover, he also parallelised Pisidice helping out the hero at the cost of her family and native land with another of his works, the Hellenistic Argonautica,[19] in which the lovestruck Medea does the same for Jason, only to be betrayed by him in the end.
[25][26] Both poems relate stories of city-sacking Achilles besieging cities like Lyrnessus, Pedasus–from which his primary concubine Briseis is also attained–[26] and others including Lesbos itself,[27] juxtaposed with his and the other Achaeans' inability to take Troy.