This article argues that the discovery of Pythagorean volumes in Numa's tomb in 181 b.c. may have played a significant role in the conception of the meeting between Numa and Pythagoras in the last book of Ovid's Metamorphoses, since several features of this event integrate very well into the discourse at the heart of Book 15 on the Greek origins of Roman culture and literature, on the immortality of poetry, and on the relationship between poetry and power. The article further (...) argues that Ennius’ Annals Book 15 may have covered the events up to 179, if that really was the year of Nobilior's dedication of the Aedes Herculis Musarum, and included the discovery of Numa's books in 181; and hence that Ovid may have used the Ennian account of this discovery as a model for the Numa–Pythagoras episode, appropriating the poetic and political meaning that it already had in Annals Book 15. (shrink)