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 Paris in the 16th century During the 16th century, Paris was the largest city in Europe, with a population of about 350,000 in 1550. The 16th century saw the Renaissance arrive in Paris, expressed in the city's architecture, art and cultural life. The Kings of France returned to Paris from the Loire Valley. Paris. In 1534 Francis I became the first French king to make the Louvre his residence. Under King Francis I, the Renaissance style of architecture, imported from Italy, was widely used in churches and public buildings, replacing the gothic style. Paris landmarks built during the 16th century