The story of the Bodhisatta, born as Chaddanta, king of elephants.
It was related in reference to a nun of Sāvatthi who, while listening one day to a sermon by the Buddha, admired his extreme beauty of form and wondered if she had ever been his wife. Immediately the memory of her life as Cullasubhaddā, Chaddanta's consort, came to her mind and she laughed for joy; but on further recollecting that she had been the instrument of his death, she wept aloud.
The Buddha related this story in explanation of her conduct. J.v.36; Speyer (ZDMG.lxxv.2, 305ff) suggests an allegorical explanation of the Chaddanta Jātaka.
Feer (JA.1895 v.) gives a careful study of the story based on a comparison of five different Versions - two Pāli, two Chinese and one Sanskrit.
This Jātaka forms the theme of many illustrations - e.g., in Barhut (Cunningham, pl.xxxvi.6), also Ajanta Caves x. and xvii.