This article is about the geographer Ptolemy. To read about Ptolemy, Alexander the Great's general, see Ptolemy I Soter.
Ptolemy (c. 90 – c. 168 AD) was a Greek mathematician, geographer, astronomer, and astrologer
Nothing is known about where Ptolemy was born or lived during his life. But he is known for his study of the heavens and for his maps. He was one of the first to try and make a complete description of the stars and planets. His model was geocentric and showed the other planets and stars as they appear from Earth.
This theory was popular for nearly 1500 years. It accurately predicted the motion of the planets better than any alternative. It was eventually replaced by heliocentric theory.