Favored and promoted by the anti-pope, Benedict XIII, of Avignon, Paul of Burgos rose higher and higher; he became bishop of Carthagena, chancellor of Castile and privy counselor to the king, Don Henry III. His malice did not succeed in prejudicing the king against the Jews, or inducing him to bar them from state employment. Don Henry had two Jewish physicians, in whom he reposed especial confidence. One, Don Meïr Alguades, an astronomer and philosopher, he appointed, perhaps in imitation of Portugal, to the chief rabbinate of the various Castilian communities. He was always in the king's train, and it is probable that to some extent he influenced him favorably towards his co-religionists. The other was Don Moses Zarzel (Çarçal), who celebrated in rich Spanish verse the long wished for birth of an heir to the Castilian throne, borrowing the beauties of the neo-Hebraic poetry to do honor to the newly-born prince, in whose hands, he prophesied, the various states of the Pyrenean Peninsula would be united. The calm, as between two storms, which the Spanish Jews enjoyed during the reign of Don Henry was favorable to the production of a few literary fruits, almost the last of any importance brought forth in Spain. None of these works was epoch-making; they were useful, however, in keeping alive the spirit of better times, and in preventing the treasures of Jewish literature from being forgotten. Profiat Duran managed to make people forget his baptism and to settle down quietly in Spain or Perpignan, where he commentated Maimuni's philosophy, and some of Ibn-Ezra's works. He also composed a mathematical and calendarial essay (Chesheb-Efod) and an historical account of the persecutions to which his race had been subjected since the dispersion. His best work is a Hebrew grammar ("Maasé Efod," written about 1403), in which he summarizes the results of older writers, rectifies their errors, and even attempts to formulate the principles of Hebrew syntax.