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 Protestants were killed in the streets by Catholic mobs. At the end of the century, Henry IV was able to return to Paris as King, and permitted Protestants to open churches outside the city. Urban innovation in Paris during the 16th century included the first street lighting, by candles.The first theater opened in Paris in 1548, and the first ballet performance took place at the French court in 1581. At the beginning of the 16th century Paris was officially the capital of France, but the King, Louis XI, had little trust in the Parisians, and resided in the chateaux of