One of the first "mythicist" books I ever read was Jesus: One Hundred Years Before Christ by Alvar Ellegård, a Swedish scholar, professor of English language and linguistics.
The thrust of his book's thesis is an exploration of the Jewish Talmud and the Toledoh Jeshu, which seem to evince a different Jesus than the one that developed into the Christian faith, as well as the Dead Sea Scrolls. In this scenario Jesus "lived" about a hundred years earlier than he is traditionally dated. Specifically, during the reign of Alexander Jannaeus (103 – 76 BCE). He doesn't quite posit an entirely cogent theory, at least for my taste. His Jesus is a mythical representation and elaboration of an Essene "teacher of righteousness" like the one featured in the Qumran library, a legendary man from an indefinite past.
At the time, I still had one foot in the historicist camp, and though his arguments are tenable, I found this book to be too reliant on speculative interpretations of the Dead Sea Scroll documents which inform them. Regardless, he made an impression on me in that, if the only record that Jews had of Jesus said that he was born a hundred years earlier, this by itself, if not enough to formulate a theory, is nevertheless a good reason for skepticism re: historicity.
- Jesus: One Hundred Years Before Christ (1999)—