Galileo was born in 1564 as the oldest son of a musician. In the 1570s the family moved to Florence, Italy. He eventually went to school at a Monastery then the University of Pisa. He started out studying medicine but developed a love of mathematics. After studying a bit, he left the university without a degree.
He continued his studies of mathematics eventually obtaining the mathematics chair in the University of Pisa. He lost that when he argued against Aristotle’s theories, so he went to the University of Padua.
In 1609, he heard about the invention of the telescope so he invented his own. Then he started studying the skies. Eventually, he started to see and wrote papers about a heliocentric universe. Basically, he said the earth revolved around the sun, with which the Catholic Church disagreed.
For this reason, they charged him with heresy. In 1633, they tried him and convicted him. Rather than death, they confined him to his rooms where he continued to study and write until his death in 1642. It took the Catholic Church until 1992 to admit they made a mistake in condemning Galileo.