Isaac ben Moses of Vienna

Isaac ben Moses of Vienna, also called Isaac Or Zarua or the Riaz, is considered to be one of the prominent rabbis of the Middle Ages. He was probably born in Bohemia and lived between 1200 and 1270. He attained his fame in Vienna and his major work, the halachic guide known as the Or Zarua a compilation of halachic decisions and legal rulings, was very popular among Ashkenazic Jewry. He was a member of the Ashkenazi Hasidim and studied under many scholars, including Eliezer ben Joel HaLevi, Judah ben Samuel of Regensburg, Samson of Coucy and Eleazar of Worms. He was among the teachers of Meir of Rothenburg.