Oh, oh, sorry about that.
Was it a cosmic joke, or just an accident of history? Everything in ancient astrology was "sidereal." Sidereal, the word, means "of the stars." Astrology was initially observational in its practice. In the middle eastern countries the stars could be best observed in the evening at the setting of the Sun, when the new/next day was believed to actually begin, or at the morning light just before the Sun rose. At those times it was easy to see which stars were setting and rising, and hence be able to judge the day/period of the year that was associated with planting, harvesting, rains, holidays, etc. Astrology was at first a means of establishing a civil calendar.
Fixed stars became associated with various human attributes depending upon the nature of the rulers who were born under them or the events that seemed to be associated with the dates upon which they rose or set relative to the Sun. Planets could be tracked observationally by their place among the many constellations that a particular culture used --- constellations being patterns of stars which could represent a person or animal or iconic figure associated with a legend or myth or archetype.
By 700 or 800 BC observational astrology gave way to the use of tables that were developed from a mathematical understanding of planet motions. This made astrology more usable. Astrology seems to have been used to assess the fortunes of kings and their generals. Yearly charts were constructed for each of these important persons based on their birth-Sun position, a form of early Solar Return charts. Kings, generals, ambassadors were all selected for assignments that fit with their annual chart.
Alexander the Great waged war and conquered much of his known world from the Mediterranean Sea to India, both causing havoc and fragmentation of knowledge and cultures as well as homogenizing portions of knowledge and cultures. From this civil mess, the Greeks gathered bits of information from everyone and, astrologically, pieced together what they found. This all took place just as the Golden Age of philosophical inquiry and mathematical curiosity was being launched. All of the great minds of the period speculated and talked of these ideas. A fellow named Ptolemy wrote many of these ideas down. Others also followed his lead.
When the Roman empire collapsed, many of the cultures north and west of Rome and Greece fell into what we call the "dark ages" in which strong central governments, centers of education and collective farming/trading practices fell apart under warring tribes and invasions of armies from central Asia. Only portions of the Arab and Persian world continued to flourish, and the discovery and practice of scientific knowledge moved forward.
With the coming and passing of the Crusade period, Europe was opened up to long lost knowledge and stronger governments and academic centers again emerged. Along with this opening up came the gradual and un-ordered discovery of long lost documents and writings. Unfortunately for logical continuity, Ptolemy's writing were discovered earlier than other documents and were taken up as "gospel" truth --- as wrong and as misguided as they were in terms of relating the practices of cultures earlier than his time.
As it turned out, the Greeks had twisted up some of their found knowledge and misapplied it, in terms of astrology. As Minderwiz pointed out, the Sidereal Zodiac (as we call it today) and the newly discovered Tropical Zodiac (as the Greeks named it and developed its use) were coincidentally in the same position during the years surrounding 221 AD. Although other cultures knew that the Precession of the Zodiac occurred, and could measure it, and knew it better coincided with the seasons and civil calendar, it was not the basis of their astrology.
But, Ptolemy's writings prevailed and use of the Tropical Zodiac began to supplant the Sidereal Zodiac as the centuries passed and we moved through the Renaissance periods into the 1600's, etc.
The above seem to be more-or-less the facts of the situation. What I now write becomes more intermixed with opinion.
As the Tropical Zodiac became more separated from the Sidereal Zodiac, the practice of astrology became more "tweaked" or adjusted to suit the needs of the astrologer in matching his words/predictions with reality. Take this along with the still-fragmented understanding of astrology, and you can appreciate that all kinds of views, wild ideas and half-baked astrological practice began to flourish. Along with poor astronomical tables and the uncertainty of "time" based on the few clocks found in the larger towns and cities (central square clocks) and the poor observation of Local Mean Time at one's location (sun dials are not that accurate in most cases), charts were both inaccurate and poorly assessed.
By the 1700s, books conveyed great fame and authority upon their authors, as well as helping to spread their views and fragmented knowledge. The mess that was called "astrology" was propagated. It wasn't until some genuine practitioners and thinkers started to share their knowledge that the practice of astrology (wrongly or rightly based on any set of ideas) began to coalesce and could be objectively assessed and moved forward.
By the 1800's many cultural forces impinged upon astrology, the "mystery schools" and secret societies being some of those "forces" of influence. Newspapers and weekly journals picked up on astrology. Books became more available. A practice which involved a codified set of meanings for planets, houses and signs, plus better ephemeris tables and mathematical practices for chart construction, as well as the emergence of clocks and personal time pieces, all contributed to a more-or-less centralized practice of astrology. This astrology was based on using Ptolemy's Tropical Zodiac.
In the mid-1900s, Irish astrologer and historian Cyril Fagan and his associates re-discovered the Sidereal Zodiac of ancient cultures. Along with this discovery they applied modern math and came up with today's version of Sidereal practices which is known for its accuracy of prediction compared to the (opinion of many) poor application of Tropical Zodiac based prediction.
However, the groundswell of Sidereal applications which took place in the 1970's and 1980's was not enough to breakthrough into the Tropical world of astrology, especially with its dramatic growth in the last half of the 1900's. The demise of Fagan and other early adopters of Sidereal practices has left that school of thought with very few promoters. It is my estimate that less than 1/2 of one percent of today's US and European astrologers practice and are knowledgeable of Sidereal Astrology.
The Siderealist's have never, in my opinion, clearly made a case for the interpretive meaning of their signs versus Tropical signs. Given their small numbers, I feel that it is incumbent on them to do so rather than to take the arrogant view of "let the others continue on their misguided ways." I have attempted, in my limited way, to determine the model or basis for Sidereal Sign meanings, how the differences of the two zodiacs can be accounted for in the way we apply sign-meanings. I can't even find consistent sign descriptions that define a core idea and basis for extending meanings that can be layered upon planets, planet aspect patterns, and houses. There are some published sign meaning descriptions that offer pages and pages of applied meanings, but none that "teach" the core ideas and how to build upon them to help in an astrological assessment.
Accordingly, I use precession-corrected Tropical frameworks which give me the accuracy of Sidereal charting for predictive purposes while allowing me to communicate with Tropical astrologers. I don't use anyone's signs as I have found them to be trivial at best. I use planets, houses, angularity, and timing cycles for my astrological practice.
If anyone is truly interested in pursuing Sidereal practices they can either contact me directly by e-mail,
dadsnook@charter.net, or visit my blog site at ninthhouse.wordpress.com to view examples of my predictive practices.
I will of course be happy to answer questions here. Dave