Levi ben Gershon, better known by his Latinised name as Gersonides or the abbreviation of first letters as RaLBaG (1288–1344), philosopher, Talmudist, mathematician, astronomer/astrologer. He was born at Bagnols in Languedoc, France. According to Abraham Zacuto and others, he was the son of Gerson ben Solomon Catalan.