Rabbi Avigdor Hacohen was the pupil of R. Simha of Speyer (who flourished about 1220), but he knew also R. Joel HaLevi of Bonn (who flourished about 1175). Avigdor lived in Vienna, and from there administered the religious affairs of the Jewish population of Austria.
Rabbi Avigdor Hacohen was a student of R. Simha of Speyer (who flourished about 1220), and he also knew R. Joel HaLevi of Bonn (who flourished around 1175). Avigdor lived in Vienna, and from there managed the religious affairs of the Jewish community in Austria.