Abraham bar Hiyya

Abraham bar Ḥiyya ha-Nasi (Hebrew: ר׳ אַבְרָהָם בַּר חִיָּיא הַנָשִׂיא; c. 1070 – 1136 or 1145), also known as Abraham Savasorda, Abraham Albargeloni, and Abraham Judaeus, was a Catalan Jewish mathematician, astronomer and philosopher who resided in Barcelona.

Bar Ḥiyya was active in translating the works of Islamic science into Latin and was likely the earliest to introduce algebra from the Muslim World into Christian Europe. He also wrote several original works on mathematics, astronomy, Jewish philosophy, chronology, and land surveying. His most influential work is his Ḥibbur ha-Meshiḥah ve-ha-Tishboret, translated in 1145 into Latin as Liber embadorum. A Hebrew treatise on practical geometry and algebra, the book contains the first known complete solution of the quadratic equation ${\displaystyle x^{2}-ax+b=c}$, and influenced the work of Leonardo Fibonacci.