JACOB BEN ASHER codifier of Jewish law, was born in Germany and died in Toledo. A son of Asher ben Yehiel (q.v.), Jacob helped to restore the legal casuistry over thrown by Maimonides (q.v.). Jacob ben Asher is known as the Bacal ha-turim (literally "Master of the Rows") from his chief work, the four Turim or Rows (the title is derived from the four Turim or rows of jewels in the High Priest's breastplate).
See Graetz, History of the Jews (Eng. trans.), vol. iv. ch. Weiss, Dor dor we-dorashav, v. 118-123.