The Book of the Life of Jesus (in Hebrew Sefer Toledot Yeshu) presents a »biography« of Jesus from an anti-Christian perspective. It ascribes to Jesus an illegitimate birth, a theft of the Ineffable Name, heretical activities, and finally a disgraceful death. Perhaps for centuries, Toledot Yeshu circulated orally until it coalesced into various literary forms. Although the dates of these written compositions remain obscure, some early hints of a Jewish counter-history of Jesus can be found in the works of Christian authors of Late Antiquity, such as Justin, Celsus, and Tertullian. Around 600 CE, some fragments of Jesus' »biography« made their way into the Babylonian Talmud; and in 827, archbishop Agobard of Lyon attests to a sacrilegious book about Jesus that circulated among Jews. In the Middle Ages, the book became the object and tool of an acrimonious controversy. Jews, Christians, and theists, such as Ibn Shaprut, Luther, and Voltaire, quoted and commented on Toledot Yeshu, trying to disprove the beliefs of their opponents and revealing their own prejudices. The narrative was translated into Latin and many vernacular languages and soon branched into numerous versions with only a few basic facts in common. The present publication provides researchers with reliable conclusions regarding the narrative's origin and evolution. In addition, the purchase of the volume offers full online access to a comprehensive database of Toledot Yeshu manuscripts, designed to encourage and facilitate further research about this important book in the history of Jewish-Christian polemics. All Hebrew and Aramaic manuscripts are edited in the present book and database: an unusual combination of a traditional critical edition with an electronic research tool. The database features a full-text search of all manuscripts as well as printing and downloading capabilities. The price includes access to the database (for one simultaneous user). Access for institutions is provided through the IP address, for private individuals through username and password. An activation code is enclosed in the book. Access to a free seven day trial period can be obtained here: toledot [AT] mohrsiebeck.com.