David Kalonymus ben Jacob
He wrote in 1464 two astrological treatises, the smaller of which is on the conjunction of Saturn and Jupiter. He dedicated the latter work to King Ferdinand I of Naples, and hoped thereby to obtain religious liberty for his coreligionists.
In 1466 David translated from Latin into Hebrew an astronomical work of John of Gmünd, which he called Mar'ot ha-Kokabim ("The Aspects of the Stars"). The work is a description of an astronomical instrument which had been invented at Vienna in 1417. He was invested by the king with an office, probably that of astrologer.