Although modern scholars generally refer to Demetrius III as Eukairos, all the Greek manuscripts of Josephus' War and Antiquities reponed by Niese, as well as all editors since Niese, read Akairos in the three places the nickname is found. Attestations of Eukairos (Greek and Latin Table of Contents, Latin manuscripts of Antiquities, and early editions) are best explained as secondary developments in the transmission of the text. The influence of the Greek editio princeps, which unjustifiably prints Eukairos in all three places in Josephus' text, accounts for the appearance of the nickname in all editions of Josephus' works until the mid-nineteenth century and hence for its use in modern scholarship. Since Josephus is our only source for the nickname, Demetrius III should never be identified as Eukairos. If a nickname is to be used, it should either be Akairos or one (or more) of the official names found on the ruler's coinage.