2280 years ago in Alexandria. Aristarch of Samos discovered the heliocentric system, the sun and the stars are fixed, the earth revolves around the sun. Ironically, fifteen centuries later, people were still arguing whether or not the earth is flat.
Copernicus fully used Aristarch's theory in his work. Aristarch basically knew what Copernicus and Galilei "discovered", but he lived more than 1800 years earlier. Historians have been given too little attention to Aristarch.
Archimedes, who was his pupil, wrote to King Gelon:
"You King Gelon are aware the 'universe' is the name given by most astronomers to the sphere the centre of which is the centre of the earth, while its radius is equal to the straight line between the centre of the sun and the centre of the earth. This is the common account as you have heard from astronomers.
But Aristarch has brought out a book consisting of certain hypotheses, wherein it appears, as a consequence of the assumptions made, that the universe is many times greater than the 'universe' just mentioned. His hypotheses are that the fixed stars and the sun remain unmoved, that the earth revolves about the sun on the circumference of a circle, the sun lying in the middle of the orbit, and that the sphere of fixed stars, situated about the same centre as the sun, is so great that the circle in which he supposes the earth to revolve bears such a proportion to the distance of the fixed stars as the centre of the sphere bears to its surface."
Known books of Aristarch:
No, sorry, I can't provide any amazon links :-) Here's a copy of a document of Aristarch: