Yehudah Hayy "Yahya" ben Hiyya, Nasi, Ra'is b'Rabbanan al-Tulaytula

source: Hiyya HaNasi

Has one son that is known 1) David ben Hiyya Nasi. Yehuda ben Hiyya Nasi fled Toledo for Zaragoza (later to Monzon) after Sisnando Davidiz seized Toledo.

Yehudah ibn Yahya (a/k/a "Hiyya HaNasi") was employed as a physician, teacher and interpreter by the Knights Templar AND Ramon Berenguer II. According to historians, Ramon Berenguer II was killed by his twin brother Berenguer Ramon II.

Berengeuer Ramon II only held power for 4 years – a civil war broke out resulting in him being deposed. Ramon Berenguer II's son, Ramon Berenguer III succeeded his father's killer. Toward the end of his life Ramon Berenguer III became a Templar and gave vast tracts of land and many castles to the Templars. Ramon Berenguer III gave his five Catalonian counties to his eldest son Ramon Berenguer IV, “Count of Barcelona” and Provence to the younger son Berenguer Ramon I, “Count of Provence”.

Descendants of Hiyya HaNasi were physicians and advisors to the Counts of Barcelona and Provence. In the 1080s Berenguer Ramon II's involvement in the internal strife in the Moorish taifa kingdoms brought him in conflict with El Cid. In the ensuing war the Count of Barcelona was twice taken prisoner by El Cid.