Ptolemy woodcut by Theodore de Bry (1528-1598).
Ptolemy was an astronomer, mathematician and geographer. He classified the Greek geocentric view of the universe, and calculated the apparent motions of the planets, as they were known in his time by synthesizing and extending Hipparchus's system of epicycles and eccentric circles to explain his geocentric theory of the solar system. He used at least 80 epicycles to explain the motions of the Sun, the Moon, and the five planets known in his time.
This system came to be called the Ptolemaic System and was the center of astronomical beliefs for nearly a millennium and a half. It predicted the positions of the planets accurately enough for naked-eye observations.