Hellenistic astrology, astronomy, and cosmology

Claudius Ptolemy

100 – 170

Claudius Ptolemy was a Greco-Roman mathematician, geographer, and astronomer working in Alexandria whose Tetrabiblos systematized horoscopic astrology within an Aristotelian natural philosophy framework, making it the canonical textbook of Western astrology for over fourteen centuries. Alongside his astronomical masterwork the Almagest — which codified the geocentric model of the cosmos — the Tetrabiblos shaped Islamic, Byzantine, and European astrological doctrine through the Renaissance and well into the modern era. Every practitioner of Western astrology works within a tradition ultimately derived from Ptolemy's synthesis.