Mesopotamian priests connected the sun, moon, and planets with specific divine beings, believing that each represented one facet of the universe's order and structure. Slowly these ideas spread into Greece, Egypt, Syria, and India, often carried with merchants and traders along with their goods.

The earliest surviving horoscope appeared around 410 B.C.E. on the Cylinder of Gudea from Babylon (currently residing in Oxford). It recounts a dream where a goddess studies a map of the heavens, giving brief positive and negative predictions based on her celestial observations.

By 300 B.C.E. astrologers were already refining their art. Now the sky was divided into twelve sections. During this time, Aristotle developed the principal philosophies for a far more methodical approach to this art. He also encouraged further studies into the art.

Aristotle's efforts were not to be without results. Three centuries later, Greek physician and writer Galen (C.E. 131–201) strongly agreed with Aristotle's ideas and went on to say he believed in the validity of celestial omens including astrology and other observed events like meteors.

Alexandrian astronomer Ptolemy (second century C.E.) similarly detailed in his writings, called Tetrabiblos, how celestial objects could affect human life in very complex ways. However, Ptolemy cautioned that this effect was by no means absolute.

Early astrology focused mostly on creating effective sky maps for travel, farming, and folk remedies rather than predicting the future. The concept of natal astrology wasn't introduced until 5 B.C.E. by a Greek astronomer named Eudoxus. Eudoxus's ideas were reintroduced in the fourth century A.D., but somehow did not catch on until much later.

Nearly every culture had is own system of astrology or celestial predictions. In Islamic tradition, for example, the stargazer was known as the Murajjim. It was this person's sacred duty to teach children how to pray for a “true star” that would govern the child's future. To accomplish this, the Murajjim employed the assistance of a complex tool composed of ciphers and degrees, appearing something like a compass. A complete prediction would be finalized by the end of the inquiry.

Astrological correspondences were originally based on a five-planet system consisting of Mercury, Venus, Mars, Jupiter, and Saturn (the visible planets at the time). Astrologers also based their observations on the moon and its phases for things like planting cycles (a tradition that was still common even in 1920).