Rabbi Isaac bar Sheshet, the great and famous Rabbi and codifier, was born in the city of Valencia, Spain, in the year 5086 (1326). He died at an old age, in the year 5168 (1408) in Algiers, North Africa.

In his youth he studied in the Yeshivah of the Rashba (Rabbi Shlomo bar Rabbi Avrohom Aderet) in Barcelona, where the Rashba's disciples, Rabbi Peretz HaKohen and Rabbi Nissim (RaN) of Gerona were his teachers. Rabbi Isaac settled in this city and quickly became renowned for his Torah learning, wisdom and piety. Although he did not want to occupy a rabbinical position, many scholars turned to him with their intricate scholarly problems.

Perilous times came upon him, when the leaders of the Jewish community of Barcelona were falsely accused, and arrested by the government. Rabbi Isaac, his younger brother Judah, his teacher Rabbi Nissim and his friend Rabbi Chisdai bar Jehudah Crescas among other leaders, were all arested. After a period of five months, when the accusation was found to be untrue, they were all released. Rabbi Isaac left Barcelona and settled in Saragossa. As a result of the accusations and his imprisonment, he became poor and was forced to accept the position as Rabbi in Saragossa, which he kept for four years (5130-5134). Here, also, he suffered because of his uncompromising attitude in matters of Torah and Yiddishkeit; also because of his opposition to Philosophy, which was so widespread in Spain at that time, and which was largely responsible for estranging many wealthy Jews from Judaism. He suffered a great personal loss when his older son, a dear child of eight years of age, died. In Barcelona Rabbi Isaac's younger brother Judah died, and then his mother.

Rabbi Isaac decided to leave Saragossa and he accepted the position of Rabbi in Calatand. The community of Saragossa, however, was not willing to part with him. A short while later, when the community leaders of Calatand freed him from his promise to come to them, he returned to his native Valoncia, where he set up a great Yeshivah and stayed there until the tragic year of 5151 (1391). That was the year when the terrible attacks on Spanish jewry started. Tens of thousands of Jews died for Kiddush HaShern (Sanctification of His name) and many fled from Spain. The number of Marranos, however, was even greater. The Marranos were Jews who openly pretended to accept the Christian Religion, but secretly kept the laws of the Torah.

At that time Rabbi Isaac, together with many other Jews, escaped to Algiers. Although he himself lived in great poverty, he did his utmost to help the other refugees. Here, under Mohammedan rule, the Jews breathed freely and were allowed to practise their religion openly. Many Marranos began to arrive there. The Jewish community of Algiers chose Rabbi Isaac as their Rabbi. Here also there turned up an "informer." He was one of the new refugees, who wanted to enforce his leadership on the town. He hindered the Ribash in his work, until the community leaders received a special document from the Sultan himself, recognizing the Ribash as the sole Rabbi in the city of Algiers, and without whose permission no one could become a Dayan (Jewish judge) in the city.

In his later years, when Rabbi Isaac bar Sheshet felt old and weak, he handed over his position to Rabbi Shimshon bar Zemach (Rashbatz). Rabbi Shimshon, however, refused to serve in an official capacity during Rabbi Isaac's lifetime, and only after he passed on, did Rabbi Shimshon become the official Rabbi of Algiers.

The Ribash became famous for his Responsa (decisions in Jewish law); apart from the great Talmudic genius shown therein, much can be learned about Jewish life during that period. The Ribash and his colleague, Rabbi Chisdai Crescas, were, after the death of the RaN (Rabbi Nissim), the two great luminaries who shone in the ejwish world. The greatest Torah scholars of Spain, France, Germany and Italy, etc., turned to them, especially to the Ribash, to decide their questions. The Responsa of the Ribash were first published in Constantinople in the year 5307 (1547), and since then have many times been republished. They have served, and still serve, as a guide for Rabbis and Talmudic students. The number of Responsa is 517, equal to the numerical value of the Hebrew letters HaRibash.

The Ribash, in addition to his Responsa, also wrote commentaries on the Talmud and other works, which are mentioned in the works of other Rabbis. Only his Responsa have remained intact to the present day.

The tomb of the Ribash in Algiers is regarded as a holy place, and many people go there to pray to the Almighty in the merit of the great saint who lies there. About 60 years ago, when the walls of the city were thrown down in order to enlarge the city, the grave of the Ribash had to be moved. In a skillful manner the whole grave was cut out of the earth as in one block, and it was transported on a wagon drawn by twenty horses to the cemetery in a nearby village. Almost the entire Jewish population of Algiers escorted the hearse. Within a year, the grave of the Rashbatz also had to be moved, and it was placed next to the grave of the Ribash. A few years later, an imposing tomb was built over the two holy graves, and many Jews still go there Erev Rosh Chodesh to pray there.