Copernicus was born on February 19, 1473, in Torun, Royal Prussia, in the Kingdom of Poland. His father was a merchant and his mother was the daughter of a merchant. Copernicus was given the name Mikolaj Korpernik at birth. Today he is known by the Latin version of his name. Copernicus was the youngest of four children. His father died when he was very young, and as a result of his death Copernicus was raise by his uncle, Watzenrode, who was the Bishop of Ermeland. Not much is known about the early life of Copernicus, other than he had a very religious upbringing. The religious upbringing is supported by the fact that one of his sisters became a Benedictine nun, while his only brother became an Augustinian canon.
It is believed that Copernicus's education started at St. John's School in Torun, where his uncle once taught. He next attended the Cathedral School which prepared students for university level studies. After graduating from the Cathedral School he started the University of Krakow in 1491. At this time, Krakow University was one of the best known schools for astronomical mathematics and philosophy. Soon after enrolling, Copernicus began assembling a library of astronomy books. At the same time he began analyzing the latest systems of astronomy. The systems he studied included Aristotle's theory of homo-centric spheres and Ptolemy's mechanism of eccentrics and epicycles. Ptolemy believed that the planet Earth was the fixed center of the universe and all of the stars and planets revolved around it in very complicated patterns. At this time, it was also the opinion of the majority of the population that the planet Earth was the center of the universe.
After leaving school in 1496, Copernicus spent the next few years in Italy studying Greek philosophy, church law, and medicine. He now spoke Latin and German fluently and could converse in Greek, Polish, and Italian. When he returned to Poland he became a church official at the cathedral in Frombork. The job left him the time he needed to study astronomy. From 1503 to 1512, Copernicus worked as his uncle's personal physician. During this time period he lived in the bishop's Heilsberg castle. He would stay there until Watzenrode died in 1512. Then in 1514, the pope asked Copernicus to work on a new calendar. The old one had been used since the time of Julius Caesar, and it was no longer lined up with the seasons. However, Copernicus soon found that there was not enough information available to create an accurate calender. He especially lacked information about the positions of the Moon and Sun. As a result Copernicus was forced to undertake further studies. Before long he realized that Ptolemy was wrong. Copernicus concluded that the planet Earth turned on its axis once a day as it went on to a yearly orbit of the Sun. This was a much simpler idea than Ptolemy's theory. The theory was not a new one. It had been introduced before Ptolemy by the Greek astronomer Aristarchus of Samos and was largely ignored. Copernicus set out to prove that he was right. He did so with mathematical equations and diagrams. Then in 1540 his ideas appeared in a six-part book entitled, “The Revolutions of the Heavenly Spheres.” Copernicus's new ideas were met by opposition from all directions including the Catholic Church and Martin Luther. The book was printed for the first time in 1543. Copernicus received his first published copy the day he died.