What system was developed by Ptolemy?

Ptolemy developed the geocentric model of the universe, known as the Ptolemaic system, which posited that the Earth is at the center of the universe, and that all celestial bodies, including the Sun and the stars, revolve around it in circular orbits. This model was detailed in his work "Almagest," which provided a comprehensive framework for understanding the movements of the planets and stars. The Ptolemaic system remained the dominant astronomical paradigm for over 1,400 years until the heliocentric model proposed by Copernicus gained acceptance.