The Babylonian origin

Astrology begins in Mesopotamia. What arose there and what did not can be stated fairly precisely today — the cuneiform tablets are preserved, dated and deciphered.

What comes from there

Systematic observation. Records of planetary positions, eclipses and phases of the Moon, kept over centuries. The Astronomical Diaries run, with gaps, from the seventh century BC to the years around the birth of Christ — one of the longest series of observations in human history.

The zodiac as a twelvefold division. The division of the ecliptic into twelve equal sections of 30 degrees each appears in the fifth century BC. It is a simplification made for calculation: the constellations are of unequal size; equal sections can be computed.

The interpretation of omens. The series Enūma Anu Enlil, in some seventy tablets, links appearances in the sky to consequences for king and country.

Sexagesimal arithmetic. Degrees, minutes, seconds — the units still in use today are Babylonian ones.

What does not come from there

The important part, and it is often passed over.

Babylonian interpretation was addressed to the king and the land, not to the individual person. Late Babylonian birth charts do exist — from the fifth century BC onwards, a few dozen of them are preserved — but they list planetary positions without interpreting them.

Everything that makes up later practice is missing: ascendant and houses, the doctrine of dignities, sect, the geometric doctrine of aspects, the time rulers. All of that arises in Hellenistic Egypt, centuries later. See Hellenistic astrology.

Why this distinction matters

Because the claim that astrology is “five thousand years old and unchanged ever since” is wrong in both directions.

It is old — older than most arts of interpretation still practised. And it has changed fundamentally several times: from royal omens to the birth chart, from there to Europe by way of Persian and Arabic development, and finally the break around 1900.

Knowing both is better than quoting a venerable number. Age proves nothing about correctness in any case — the doctrine of the humours was just as old, and it is gone.