Unetaneh Tokef: the tradition of Rabbi Amnon and the copies older than it

The account runs thus. Rabbi Amnon, the first man of Mainz, was pressed by the bishop to be baptised. He asked for three days to consider—and going home could not forgive himself for having asked even that. On the third day he did not come; he was brought by force, and he himself named the penalty for what his tongue had said. Maimed, he was carried into the synagogue on Rosh Hashanah, and he recited Unetaneh Tokef, and with it he died. Afterwards he appeared in a dream to Rabbi Kalonymus ben Meshullam and asked that the prayer be sent to all the communities.

The account was written down by Rabbi Isaac of Vienna in the Or Zarua, and he cites Rabbi Ephraim of Bonn—that is, a generation that still remembered the massacres of the First Crusade. This is not late invention: it is the Ashkenazi community's memory of its martyrs, and it is what carried the prayer from the Rhine to the ends of the earth.

And, apart from that, something else is true. In the Cairo Genizah copies of Unetaneh Tokef were found older than this tradition and coming from where Mainz had never been heard of. Among the names scholars propose are the payyetanim of the Land of Israel Yannai and Yose ben Yose; Rabbi Elazar ha-Kalir has a kedushta with turns of phrase so close that the prayer appears to be older than he is too.

Both stand side by side, and neither cancels the other. The prayer came out of the Land of Israel long before Mainz—and it was Mainz that made it universal, by giving it to a man who died rather than consent.