De revolutionibus orbium coelestium have begun work on his new system by that time. Most historians believe that he wrote the "Commentariolus" after his return from Italy, possibly only after 1510. At this time, Copernicus anticipated that he could reconcile the motion of the Earth with the perceived motions of the planets easily, with fewer motions than were necessary in the "Alfonsine Tables", the version of the Ptolemaic system current at the time. In particular, the heliocentric Copernican model made use of the Urdi Lemma developed in the 13th century by Mu'ayyad al-Din al-'Urdi, the first of the Maragha astronomers to develop a non-Ptolemaic
Paris in the 16th century the 16th century, Paris became first in Europe in book publishing. In 1530, Françis I created a new faculty at the University of Paris with the mission of teaching Hebrew, Greek and mathematics. It became the "Collège de France". In 1540, the Jesuit order established its first schools in Paris. In 1549, the first textbook of the French language, "Defense et illustration de la langue Française", by Joachim de Ballay, was published. Francis I died in 1547. His son, Henry II, made his official entrance into Paris in 1549 with a lavish procession and ceremony; the first Renaissance fountain in