  This article aims to contribute to two well-worn areas of debate in classical
Latin philology, relating to Ovid's Heroides. The first is the question of the
authenticity (and, to a lesser extent the correct position) of the letter
placed fifteenth by almost every editor -- the so-called Epistula Sapphus
(henceforth ES). The secondary question, although perhaps now less fervently
debated, is the authenticity of the 'Double Heroides', placed by those who
accept them as letters 16-21. I employ a variety of methods drawn from the
domain of computational stylometry to consider the poetics and the
lexico-grammatical features of these elegiac poems in the broader context of a
corpus of 'shorter' (from 20 to 546 lines) elegiac works from five authors (266
poems in all) comprising more or less all of the non-fragmentary classical
corpus. Based on a variety of techniques, every measure gives clear indication
that the poetic style of the Heroides is Ovidian, but distinctive; they can be
accurately isolated from Ovid more broadly. The Single and Double Heroides
split into two clear groups, with the ES grouped consistently with the single
letters. Furthermore, by comparing the style of the letters with the 'early'
(although there are complications in this label) works of the Amores and the
late works of the Ex Ponto, the evidence supports sequential composition --
meaning that the ES is correctly placed -- and, further, supports the growing
consensus that the double letters were composed significantly later, in exile.
