RABBI YAAKOV SHAUL ELIASHAR (or Elyashar) was CHACHAMBASHI (Chief Rabbi) of Jerusalem; born at Safed, June 1, 1817. He was taken to Jerusalem in 1823. He was the grandson of Rabbi Yaakov ben Chaim Eliasher. His father, Eliezer Yeruchim was a Dayan, shochet, and chazzan in Sefad. He was arrested by the Turkish authorities in Safed, but succeeded in escaping and settled with his family in Jerusalem. When Rabbi Yaakov Shaul was seven, he lost his father. His mother remarried in 1828 to Rabbi Benjamin Mordecai Navon. His stepfather became his teacher and supported him for many years.

Rabbi Elyashar married the daughter of Rabbi Rafael Meir Panigel. He rapidly became known as an outstanding Torah scholar and enjoyed tremendous respect. In 1853 he was appointed a Dayan in the Sephardic Beth Din of Jerusalem under Rabbi Abraham Ashkenazi. In 1855 Rabbi Eliashar was appointed Associate Chief of the Beth Din. In 1869 Rabbi Elyashar took over as the new head of the Beis Din. In 1880 Rabbi Elyashar was invited to the position of Chachambashi of the Ottoman Empire but he deferred this position to his father in law Rabbi Panigel until 1893 when his father in law passed away and Rabbi Eliashar was appointed as the new Chachambashi, a position he maintained until 1904 at a very advanced age.

In 1893 His Imperial Majesty, the Sultan AbdulHamid II, Emperor of the Ottoman Empire confirmed his appointment in a official Firman, sending him an official robe and a medal of the Medjidie order. In 1898, when Emperor William II of Germany visited Jerusalem, Rabbi Eliashar together with Rabbi Shmuel Salant, Chief Ashkenazi Rabbi of Jerusalem, welcomed the Emperor who presented them with a medal. Rabbi Yaakov Shaul Eliashar spoke Ladino, Spanish, Hebrew, Arabic, Turkish, Italian, and Greek which served him well in his capacity as Chachambashi. Ladino was the primary language among the Sephardim of Jerusalem.

Rabbi Eliashar took responsibility for the wellbeing of the Sephardic community in Isreal and traveled to Turkey, Syria, Egypt and Italy on missions on their behalf. He became very close to Rabbi Shmuel Salant who was in charge of the Ashkenazi community. They worked tirelessly together on many projects for the benefit of the public. Rabbi Eliashar would consult with Rabbi Salant on every important matter that was on the agenda in Palestine. Rabbi Eliashar assisted Rabbi Salant with the Rabbi Meir Baal Haneis Salant charity fund which supported the Ashkenazy community.

Rabbi Yaakov Shaul Eliashar authored a large body of Torah literature in all facets of Judaism, including Simla leIsh, Ma'aseh Ish, Shoel Ish, and Ish Emunim. A cultured scholar and a fluent linguist, Rabbi Elyashar wrote thousands of responsa in answer to questions from both Ashkenazim and Sephardim all over the world. He was respected by the authorities and the heads of other religious communities, He also corresponded with most of the leading Rabbinical authorities of his time including Rabbi Yosef Chaim (1834-1909), one of the most revered rabbi of the generation, known as the Ben Ish Chai. Rabbi Yosef Chaim asked Rabbi Eliashar to assist Babylonian rabbis who wished to immigrate to Jerusalem. He was also instrumental in the complex issue of men who left Baghdad to settle in Jerusalem and abandoned their wives and families.

In 1904, due to old age, he relinquished his position as Sephardic Chief Rabbi and two years later, in 1906, he passed away. He was mourned by the entire Jewish community, Sephardi and Ashkenazi alike. He was buried on the Mount of Olives. The Givat Shaul district of Jerusalem is named after him.