Elijah ben Moses Bashyazi of Adrianople or Elijah Bašyazi (in ) (c. 1420 in Adrianople – 1490 in Adrianople) was a Karaite Jewish hakham of the fifteenth century. After being instructed in the Karaite literature and theology of his father (Moses Bashyazi) and grandfather (Menahem Bashyazi), both learned hakhams of the Karaite community of Adrianople, Bashyazi went to Constantinople, where, under the direction of Mordecai Comtino, he studied rabbinical literature as well as mathematics, astronomy, and philosophy, in all of which he soon became most proficient. Hakham at Adrianople In 1460 Bashyazi succeeded his father as hakham of the Karaite community at Adrianople. From the many letters addressed by him as representative of the Karaite community of Constantinople, from 1480 to 1484, to Karaim communities in Lutsk and Trakai. Neubauer concludes that Bashyazi resided for the most of the time in Constantinople. In these letters he appears as a warm-hearted defender of the Karaite faith. He urges his coreligionists to send young men to Constantinople to study their religious authorities, lest their faith die out, and to lead a pious life; otherwise he would pronounce an anathema on those derelict in their duties. He devoted himself to the improvement of the intellectual condition of the Karaite etc., which, in consequence of internal dissensions on religious matters, was at that time very low. Aderet Eliyahu In order to settle the religious laws he compiled a code entitled Aderet Eliyahu (The Mantle of Elijah). This code, which contained both the mandatory and prohibitory precepts, is rightly regarded by the Karaites as the greatest authority on those matters. In it Bashyazi displays a remarkable knowledge, not only of the earliest Karaite writings, but also of all the more important rabbinical works, including those of Saadia Gaon, Abraham ibn Ezra, and Maimonides, whose opinions he discusses. The "Aderet" is divided into subjects and these again are subdivided into chapters. The subjects treated are: (1) the fixation of the months (42 chapters); (2) the Sabbath (22 chaps.); (3) Passover (10 chaps.); (4) matzah (7 chaps.); (5) the Feast of Weeks (10 chaps.); (6) Rosh Hashannah (2 chaps.); (7) Yom Kippur (5 chaps.); (8) Sukkot (5 chaps.); (9) prayer. This last subject comprises three parts: theology; ethics; and laws concerning prayers, synagogues, slaughtering, clean and unclean, prohibited degrees in marriage, niddah, the years of release and jubilee, the prohibition of Shatnez, and oaths. The last three