There is evidence that numerology was in use thousands of years ago in China, Greece, Rome, and Egypt -- long before the time of Pythagoras, who is generally accepted as the "father" of numerology. King Sargon II, who ruled Babylonia in the 8th Century BC used the numerical value of his name to determine the length of a wall in the city. Most of the earliest teachings were transmitted orally, only to the initiated, because the information was considered very powerful and sacred. Pythagoras, a philosopher and mathematician, lived and taught in Southern Greece in the sixth century B.C. Before settling down in Greece and establishing the world's first co-educational university for esoteric studies in Croton (modern Crotone), in southern Italy in 532 BC, he spent more than 20 years in Egypt and Babylon where he was initiated to the secret cults and magic practices.

From certain observations in music, mathematics, and astronomy, he believed that all relations could be reduced to number relations ('all things are numbers'). The teachings of Pythagoras were taken up by Plato and reinforced by the writings of the Jewish Cabala. Although little can be confirmed about Pythagoras directly, his teachings spawned a philosophical and religious movement, called Pythagorism, that spread throughout the Roman Empire. In the Middle Ages, a numerical mysticism evolved from the teachings of Merkabah, a sect of Judaism. In the 13th century the German Kabbalists developed gematria, a mystic numerical interpretation of the Scriptures. Continued interest by early Christian scholars, such as St. Augustine, led to the widespread use of numerology during the Renaissance. For their readings, modern numerologists have adopted the original Pythagorean system. During the 19th century, when scientific discoveries concerning light, magnetism, and electricity were being made, the theory that numbers corresponded to energy patterns of vibrations became popular.