Rus' Khaganate
Throughout the late nineteenth and early twentieth centuries Brutzkus authored a vast array of articles and books in Russian, Lithuanian, Polish, English, German, Yiddish, Hebrew, and French on the history of the Jews in Russia; he was particularly intrigued with the history of the Khazars and the early Rus' Khaganate. He also wrote numerous works on the economic and political history of Eastern Europe and the cultural history of Mizrahi Jewry.