Written by Eleazar Kallir it became part of the Romaniote liturgy in the 7th century from which it passed into the Ashkenazi and Sephardic liturgy. It is an extremely important piyyut for Messianic Noahites to say on Yom Kippur. The Messianic Chabadniks have been making a concerted effort to get it removed from all Machzorim.