Rabbeinu Yaakov Baal Haturim was born to his father the Rosh in the year 5030 (1270) in Germany. He was extremely wise, pious, humble and holy. He was a student of both his father and older brother Reb Yechiel. At the age of 23 his father together with his entire family escaped to Toledo, Spain but he remained behind in Germany. He was destitute and worked very hard to eke out a source of livelihood. However, he later also emigrated to Barcelona, Spain and then on to Toledo. He had a younger brother Reb Yehuda who eventually married his daughter before succeeding Rosh as Rabbi of Toledo. Rabbeinu Yaakov took a position in the Beis Din.
His magnum opus was his Arba Turim in which he codified all the law relevant to Jews nowadays, quoting the opinions of all the great Rishonim who lived until his time. It was so called as it was divided into 4 sections; daily life as a Jew, Dietary laws and laws concerning idol worship and bereavement, monetary laws and marital laws. This work was the foundation for the classical Shulchan Aruch written approximately 300 years later by the great Rav Yosef Karo. This work was so famous that lots of great Torah giants in the centuries that followed authored commentaries on his work. These include the Beis Yosef, the Rama, the Bach, Maharam Alashkar and Mahari Abuhav amongst others. He also composed a work in which he summarised the lengthy commentary of his father’s into clear and succinct passages known as Kitzur Piskei Harosh. He also authored an original commentary on the Chumash of which there is a long and short version. This commentary is replete with beautiful commentaries and Gematrias and also points out instances of Bible Concordance.
The Chida wrote about him that one cannot properly begin learning Halacha without first learning the Turim. The Maggid of the Beis Yosef would call him ‘’Yaakov the G-d fearing one’’.
He attempted to emigrate to Eretz Yisrael but passed away on the way in the city of Kio* on the 12th of Tammuz 5108 (1348).