From the Chaldeans, astrology spread to the Greeks, who further developed it and introduced it to the Western world. The Greek astronomer and mathematician Claudius Ptolemy wrote the influential book Tetrabiblos, which laid out the principles of astrology as it was practiced in the Greco-Roman world.
Astrology continued to be widely practiced throughout the Middle Ages and Renaissance and was considered a legitimate science. However, with the rise of modern science and the development of rational and scientific methods of studying the universe, astrology began to lose its credibility and was eventually dismissed as a pseudoscience.