Nicolaus Copernicus (Thorn 1473 – Frauenburg, modern-day Frombork, 1543), Polish astronomer and cosmologer noted for his astronomical theory known as the “heliocentric theory” or “heliostatic theory”, at the basis of which is an immobile Sun at the centre of the Universe and the Earth, which rotates daily on its axis, orbits around it over the course of a year.

Early life and education
Copernicus was born in today’s Poland to a German-speaking family of merchants and high officials originally from Silesia.
His maternal uncle, Bishop Lukasz Watzenrode, provided for his nephew’s solid education. He began studying at the University of Krakow in 1491, where he read liberal arts for four years without, however, taking his degree; he subsequently went on to study Medicine and Law in Italy, like many other young Poles of his social status.
In the meantime, his uncle had him take on a canonry of an administrative nature which needed minor orders in Frauenburg.
In January 1497 he began to study Canon Law at the University of Bologna and deepened his studies into Classical Literature; at that time he was the guest of a highly important Mathematics professor, Domenico Maria Novara, one of the first critics of the 2nd century AD astronomer Ptolemy’s Geographia. He encouraged Copernicus’s interest in Geography and Astronomy and together they observed the occultation of the Aldebaran star, which took place on the 9th of March, 1497.
In 1500 Copernicus began teaching Astronomy in Rome; the following year he obtained permission to study Medicine at Padua (at the University where Galileo would teach almost a century later). Since at that time it was normal to study a subject at one University and graduate from another, even though he had not finished his studies in Medicine, he graduated in Canon law in Ferrara in 1503 and returned to Poland, having been summoned to return to his administrative duties.

The return to Poland
From 1503 to 1510 Copernicus lived in his Uncle’s Episcopal palace in Lidzbark Warminski, collaborating in the administration of the diocese and the fight against the Order of the Teutonic Knights, but continuing at the same time with his astronomical observations. Between 1507 and 1515 he prepared a treatise on astronomy in which he briefly outlined his heliocentric theory for publication. The treatise, entitled De hypothesibus motuum coelestium a se constitutis commentariolus (known as Commentariolus), which appeared exclusively in manuscript form was only published in the 19th century.
After moving to Frauenburg in 1512, he took part in the commission of the Fifth Council of the Lateran on Calendar Reform (1515), wrote a Treatise on Money (1517) and began to compose his most important works, the De revolutionibus orbium celestial (On the Revolutions of the Heavenly Spheres), which he completed in 1530. This work was published in Nuremberg by a Lutheran printer shortly after Copernicus’s death.