As is well known, the work of Aristarchus on Homer is not preserved by direct tradition. We have instead many fragments preserved mainly in the Homeric scholia, the Byzantine Etymologica and the Homeric commentaries by Eustathius of Thessalonica. These fragments go back to the so-called Viermännerkommentar (abbreviated VMK), the ‘commentary of the four men’, a commentary that is dated to the fifth-sixth century c.e. and collects the works of Aristonicus, Didymus, Nicanor and Herodian. In the first century b.c.e. Aristonicus explained the meaning of Aristarchus’ critical signs in a treatise called Περὶ τῶν σημείων τῶν τῆς ᾿Ιλιάδος καὶ ᾿Οδυσσείας, while in the Περὶ τῆς ᾿Αρισταρχείου διορθώσεως Didymus studied Aristarchus’ Homeric recension. In the second century c.e. two more scholars, Herodian and Nicanor, dealt with Aristarchus while analysing questions of prosody in the Homeric language (Herodian) or the punctuation of the Homeric text (Nicanor). Not all of these four ‘men’ are equally important, however, as sources for Aristarchus. In fact, Herodian and Nicanor had aims that were quite independent of Aristarchus’ enterprise: the former was concerned with problems of prosody, accentuation and aspiration in Homer, whereas the latter had developed a new system of punctuation to elucidate the Homeric text from a syntactic point of view. Although both Herodian and Nicanor did take an interest in Aristarchus, their focus was thus different from that of their Alexandrian predecessor. The goal of Aristonicus and Didymus, on the other hand, was specifically to reconstruct Aristarchus’ work on Homer; it is for this reason that they are considered the most trustworthy witnesses for Aristarchus’ fragments.