A Commentary on the Jātaka. It comprises all the verses of the Jātaka and gives also, in prose, the stories connected with the verses. Each such story is given a framework of introductory episode, stating the circumstances in which the story was related, and each story has at the end an identification of the chief characters mentioned with the Buddha and his contemporaries in some previous birth.
The whole collection is prefaced by a long introductory essay, the Nidānakathā, giving the Buddha’s history before his birth as Siddhattha, and also during his last birth, up to the time of the Enlightenment.
The work is a translation into Pāḷi of the commentary in Sinhalese as handed down in Sri Lanka, but the verses of this commentary were already in Pāḷi.
The authorship of the translation is traditionally attributed to Buddhaghosa, but there exists much difference of opinion on this point. For a discussion see P.L.C.123 ff.
The English translations can be found online: Sacred Texts.