Polish rabbi of the first half of the sixteenth century. He was at first rabbi of Posen, and a decision rendered by him there on a question of divorce is mentioned by R. Shaknah of Lublin (see "Ḥelḳat Meḥoḳeḳ" on Eben ha-'Ezer, 45). Later he became rabbi of Brisk or Brest-Litovsk, and an order issued by King Sigismund I. (Sept. 4, 1531) commanding the Jews of Brest-Litovsk to submit to R. Mendel's jurisdiction proves either that he was not popular in that place, or, as Bershadski contends ("Litovskie Evrei," p. 377, St. Petersburg, 1883), that the Jews of Lithuania did not like the newly instituted rabbinical jurisdiction over their affairs, preferring to submit their differences to the general authorities. There is also extant a letter from Queen Bona, dated May 28, 1532, ordering the starost of Brest not to recognize appeals of Jews from the decisions of R. Mendel Frank and not to interfere with him in any way. The interest which the king and the queen took in R. Mendel, and the antagonism of the Jews, make probable the conjecture that he was not chosen rabbi by the community, but was forced upon it by Michael Esofovich, who was made chief of the Jews of Lithuania in 1514, and had, among other privileges conferred upon him by the king, the right to appoint rabbis.
- Feinstein, 'Ir Tehillah, pp. 21-22, 164, 202, Warsaw, 1886
- Bershadski, Ruski Evreiski Archive, i., No. 139, St. Petersburg, 1882.