The adoption of astrology by the Greek is the most prominent. The Greek elevated astrology to a science, applying precision astronomy and mathematics. This all happened in the Neo-Assyrian period (600 B.C. – 100 B.C.)
Everyone will remember their first experience with Pythagoras (+/- 500 BC – † 580 BC) in junior high, as he is attributed a theory in Geometry. He is also the one we suspect to have brought astrology to Greece, later followed by Berossos. It is claimed Pythagoras lived in Chaldea*, and had come in contact with the great Babylonian astrologers. In astrology Pythagoras is responsible for the theory he called ‘The harmony of Spheres‘. This theory states that planets would make ultrasonic sounds depending on their position in the heavens. Later Pythagoras would establish a school of Philosophy which had a great influence on Greek culture.
The Chaldean priest Berossos (330-323 B.C. – †?) finalized the introduction of astrology when, in the 3rd century BC, he established the first school of astrology on the Greek island of Kos. In Greece, and most likely in Berossos’ school, the natal chart arose. The positions of the planets important to the individual.
The third VIP to mention from Greece is Ptolemy (83 AD – † 161 AD). He is known for his comprehensive treatise on astronomy, which he called ‘The Almagest’. Only few know that the ‘rather small addendum’ of four books named ‘The Tetrabiblos‘ was fully dedicated to the art of astrology. Ptolemy was also the first one to take Pythagoras’ ‘Harmony of Spheres’ and put down in writing what we now know as ‘the Ptolemaic aspects’ in astrology. The Ptolemaic aspects or Major Aspects are the angles in which planets ‘resonate’ and appear in the skies**.
* Chaldea can be used in two ways: either referencing to the entire region of Babylonia (later), or a region in the south of Babylonia, near the city of Ur (earlier).
** 0 degrees: conjunction, 60 degrees: sextile, 90 degrees: square, 120 degrees: trine, 180 degrees: opposition.
Astrology in the Roman empire
In the same timespan astrology also had a large following in Rome, those in power were not the greek astrologers but priests from Chaldea. Between 300 B.C. and early in A.D. many roman emperors have let themselves be advised by astrologers, including Julius Ceasar. It was Augustus who even pushed a law that astrology shouldn’t be used outside politics. This made astrologers outlaws together with early christians. Both were persecuted in the roman empire. Right after christian religion had established itself, the church started doing the same thing the romans did to the astrologers. They used their knowledge but made sure nobody else could practise it. It is speculated that the three Kings (Gaspar, Melchior and Balthazar) were actually astrologers.
Arabians to Middle Ages
The Arabs in this context actually are Egyptians, Persians*, Byzantians**, Syrians and Chaldeans. As was usual in these times, astrologers were also astronomers, mathematicians, scientists, writers, poets, alchemists. Islam appeared in the 7th century A.D. And like the christian tradition, Islam was pretty much hostile to astrology as well. That didn’t keep followers of Islam from practising it.
The single most valuable contribution came from Al-Kindi (801 – † 873 A.D.) in the 9th century. He translated more than 200 greek works in his own language. Another man of importance was Albumasur (787 – †886 AD). He is the first to have written about astrological ages, like the piscean age, the aquarian age. He explained this using precession of the equinoxes.
A lot of Arab works had been translated into Latin, this also was the case for Albumasur’s most important work: ‘the flowers of astrology’, eventually having a great influence on the empire of Karel de Grote*** (“Charles the Great”) in the first century.
* The Persian empire was a series of historical empires that ruled over the Iranian plateau, the original Persian homeland, and beyond in Western Asia, Central Asia and the Caucasus.
** The Byzantine empire is another way to describe the Roman empire of the middle ages. It includes Greece.
*** Map shows the empire of Karel de Grote, stretching current France, Belgium, the Netherlands and part of Germany.