Abraham bar Ḥiyya (d. ca. 1136) was a philosopher, astronomer, mathematician, and translator who worked at the Christian court of Barcelona and perhaps for Alfonso I of Aragon. Very little is known about his life other than an altercation he had with Judah ben Barzillay al-Bargeloni in connection with a wedding that Bar Ḥiyya felt ought to have been postponed for astrological reasons. It is also known that he visited France. He was still active in 1136, when he was last mentioned as a collaborator by Plato of Tivol…