born 1269?, Cologne?
died 1340?, Toledo, Castile
Jewish legal scholar.
He emigrated to Spain with his family in 1303, and his father became chief rabbi in Toledo. Jacob is believed to have made his living as a moneylender. He divided Jewish law into categories by subject, producing a codification known as Tur , which became a popular Jewish theological work of the 15th century. The basis for many rabbinic decisions, it was considered standard until superseded by the work of Joseph ben Ephraim Karo in the 16th century.