Copernicus

Copernicus was a 15th Century and 16th Century Polish Astronomer. In 1530 Copernicus completed his seminal work written in Latin, "De Revolutionibus Orbium Coelestium" loosely translated into English that means "about revolutions of celestial (spheres/bodies)"".  Copernicus recognised that the Earth rotates on its axis, also that the earth and the other planets orbit the sun.  This is known as a Heliocentric theory.

Copernicus wasn't the first to introduce Heliocentrism, Aristarchus of Samos was the first astronomer known to Historians who introduced a heliocentric theory.