Messiah (mâšîah, "the anointed one"): Jewish religious concept, a future savior who will, in some sense, come to restore Israel. The nature of both the Messiah and the restoration wasa matter of debate, and there were several claimants.
Abu Isa' al-Isfahani
The rise of Islam and the end of the great wars of the first half of the seventh century greatly improved the conditions of the Palestinian peasantry. Many Jews converted to the new faith, provoking a crisis withing Rabbinical Judaism in Palestine. Around 700 CE, one Abu Isa' al-Isfahani proclaimed that he was the Messiah. He rejected the authority of the Talmud, and in his teachings he combined elements of Christianity, accepting Jesus and Muhammad as the greatest prophets ever.
His sect was violently repressed by the Arab authorities; Abu Isa' and most of his followers were defeated in battle. Those who survived, claimed that their Messiah was not dead, but had retired to a mountain, from where he would one day return.