We would have been dependent on the Sun to provide warmth and light and would have awaited its' return each morning after it had mysteriously disappeared each evening.
While the Sun had disappeared and taken its' light and warmth with it, the Moon would have provided at least some vision on most nights. Obviously, a moonless night would be very dark whereas a night with a Full Moon would at least give some night vision.
If we were still reliant on the Sun for warmth/light and the Moon for night vision then we would probably find the changes and activities associated with the Sun and Moon much more prominent in our lives right now.
After a period of time the Moon's cycle would have become apparent? New Moon, First Quarter, Full Moon, Third Quarter and then to New Moon again. I know that if I noticed this pattern with the Moon, that I would want to find out whether or not other celestial objects followed a cycle too.
During the process of following the movement of the planets, records were kept by the astronomer/astrologers (these fields didn't become individual ones until the late 17th century). Eventually it was discovered that the position of the planets seemed to relate to activities here on earth. Welcome to the birth of astrology!
Of course the astrology that began thousands of years ago was not what we have now. It went through a process of development and fine-tuning. In a broad sense astrology went through three stages of development: the first stage where planetary positions/movements were related to events on earth; the second stage where the zodiac is used; and the third stage where personal charts made an appearance.
Stage One: How it All Began? (I think!)
The earliest known practice of astrology, the origin of western astrology, is evident in the Mesopotamian region during the Sumerian civilization (3000 BC), also known as the Old Babylonian period. This consisted of observations of stars and the planets, but not the use of houses or the zodiac.
The oldest astrological document still in existence is the work "Namar-Beli" (Illumination of Bel) composed in cuneiform for King Sargon I (end of the third millenium BC).
Stage Two: Welcome to the Zodiac!
From Stage One where the movement of the planets were noted in relation to each other, it looks as though astronomer/astrologers from about 630 to 450 BC began to divide the ecliptic into twelve zodiac signs of 30 degrees each. It is thought that this system was developed by the Late Babylonians.
Stage Three
The next stage of astrological development involved the use of the personal horoscope. The oldest birth chart that has been professionally dated is one written in cuneiform for April 29, 410 BC. The zodiac positions recorded in the horoscopes that have survived these periods are closer to the sidereal astrology rather than the tropical.
