Roman astrology in the ascendant

While the knowledge of the practice of astrology in antiquity has been shrouded by the mists of time, some important truths have survived to this day.

We know that Alexander "the Great" opened Greece up to the ancient practice of Chaldean astrology, which was linked to Egyptian astrology and possibly also to the astrology of the Vedas. In turn, Hellenic astrology subsequently informed Roman astrology as the civilizational thrust moved westward.[1]

While closer to us in time, there is little known about the practice of astrology in Roman times. However, there are some important insights that have survived. An essential truth concerning Roman astrology as it was practiced more than two millennia ago is that it placed prime emphasis on the ascendant in interpreting the horoscope, in line with the horoscopic astrology of the Hellenic world [2] . In fact, some even suggest the astrology in Roman times was the same as Hellenic astrology[3].

Octavian "the Capricorn"
According to the poem Astronomica, which was written in the early first century A.D. by a poet named Marcus Manilius, the rising sign was taken as the sign under which one was born. According to modern Western notions Emperor Octavian, who was born on September 23, 63 BC, would have been born with the sun sign of Libra as per the zodiac in use in his day and thus be considered a "Libra".[4] However, in Roman times it was noted by Manilius that "Capricorn [was] the sign under which he was born."[5] It is of importance to note that he was considered to be born under his rising sign, and not the sun sign*. This is further evidenced by the fact that Octavian, or Augustus as he became known as Emperor, had his rising sign with a fish "tail" minted on the back side of a Roman coin bearing his image on the "head".

Ascending sign or Sun sign?
The Vedic astrology of today also places prime importance on the ascendant when interpreting the horoscope. It has retained the link to its ancient origins. By comparison, the emphasis that modern Western astrology places on the sun sign is likely a more recent invention. That said, the Sun is without a doubt the single most important heavenly body, representing as it does the spirit of man and the evolution of the soul. By comparison, the ascending sign and its ruler give the psychological and physiological make-up of man and are the basis for ordering the karmic nature of the planets in the horoscope as per their house rulership.

Important breakBut why did the shift take place?
A key element in the break between modern Western astrology and its ancient forerunners occurred in the 3rd century AD[1]. This was the practice of correcting for the precession of the equinoxes. From Babyloninan astrology and well into Roman times the sidereal zodiac was used.[6] The objective of the correction is to maintain correspondence of the calculated zodiac to the cosmic background of the visible constellations. The ancient astrologers new about the precession and compensated for it. However, for some reason the solar reference to the Vernal Point in the Spring became a new benchmark for astrologers in Rome. In not making the correction, the 0° Aries point in the tropical zodiac began to drift from the 0° Aries point in the visible sidereal zodiac. This technical shift evidently made the Sun more important for the overall consideration. In this regard, we should keep in mind two things, a) the rise of Christianity in the 3rd century and b) the total collapse of the Western Roman Empire in the 5th century. Together, these events ushered in the birth of Western civilization. However, far from its modern glory, the early beginnings were a picture of complete social and intellecutal breakdown, described as the dark ages. The true rise of Western civilization took place with the renaissance of the late middle ages, which was fueled with ideas and knowledge from the Arab world. The immediate result of the breakdown of pagan Roman civilization is that the connection with the practice of horoscopic astrology of ancient Rome was for the most part shattered. "After the fall of Rome, there was almost no astrology in the West until the 11th and 12th centuries"[7]. With the rediscovery of astrology in Europe in the late middle ages, it was the sun-sign that became its centerpiece. The birth of modern Western astrology thus represents a clear break with the tradition of horoscopic astrology of ancient Rome, and which is still practiced in India. Adding to the divergence is the compelling fact that the new branch of western astrology evolved based on a zodiac moving with respect to the galactic background while Vedic astrology retained its link with a zodiac firmly anchored on the visible fixed stars.

The constancy of the Ides
History records that the Ides of March (literally, the change of signs in March) was the time when a Roman astrologer warned Julius Caesar about two thousand years ago to take care. While Caesar did not heed his warning, the Sun on March 15, 44 B.C.E. passed into the sign Aries in the sidereal zodiac. It no longer does so, due to the precession of the equinoxes.

By comparison, in the tropical zodiac, the Sun was at 24° Pisces in Rome on that fateful day two millennia ago (adjusting for the change from Julian to Gregorian calendars in the late 16th century). It still makes the appearance there today. This is because western astrology is based on a zodiac that has as its reference the movement of the sun with an emphasis on the regular appearance of the solar seasons. In doing so, the tropical zodiac lost its moorings in the cosmic background, or the visible fixed stars that make up the signs. 

By comparison, the Sun now enters Pisces in mid March in the sidereal zodiac of Vedic astrology. This is because the precession of the equinoxes has moved the constellations backwards by almost one whole sign as seen from the earth in mid March over two millennia later. 

In a few hundred years from now the difference between these two zodiacs will be a whole sign, or 30°. Surely, if the constellations and the signs which they make up have meaning at all as reference points in the sky, then this would matter for the interpretation of the influences emanating from the regions of the cosmos. Moreover, as the precession-adjustment gained importance, the focus of the reading apparently and gradually was deflected away from the primacy of the ascendant and house rulerships as in ancient astrology to the placement of the Sun by sign in modern Western astrology. In some sense, the sun had become the fixed star of Western astrology.

Vedic astrology is closer to Roman astrology
Considering that Western astrology has also by now included the outer planets and minor bodies in the solar system, all of which are invisible to the human eye, there is no doubt that it has thoroughly departed from its historical origins in Hellenistic and Roman astrology. In fact, it is modern Vedic astrology that is the closest living relative of the ancient traditions. Importantly, in addition to the different zodiacs, the Western and Vedic forms of astrology now represent radically different approaches to horoscopic interpretation, with one focused on the sun sign while the other begins with the ascendant. The extent of the divergence is not always fully understood or appreciated, including the use of planetary periods in Vedic astrology.
Planetary periods
As in ancient Egyptian astrology, it is possible the Romans also used planetary periods, in addition to transits, when explaining the past and predicting the future. This would have been another similarity with the Vedic astrology tradition.[8] Planteray periods reveal the general trends operating at different stages in the life while transits indicate the nature and timing of significant events. Such systems have evolved through the eons due to the gift of insight by great astrologers, both past and present. The aim has always been to discern the pattern which gives the most accurate reading of a horoscope and predictions for the future.

With hindsight, Caesar would undoubtedly agree that the practice of astrology in Roman times was keyed to predictive accuracy. This is also very much the case with Vedic astrology today.

Footnote
*) Gaius Julius Caesar Augustus was born sometime between 1 PM to 3 PM on September 23, 63 BC in Rome, giving Capricorn as the rising sign. His Sun was at 4° Libra in the tropical zodiac (9° Libra in the sidereal zodiac). The Moon was at 29° Libra in the tropical zodiac (4° Scorpio in the sidereal zodiac). Importantly, this excludes the possibility of Capricorn being his Moon sign.

Source
[1] History of Astrology
http://en.wikipedia.org/wiki/History_of_astrology
[2] Dr. Gustav-Adolf Schoener, “Astrology: Between Religion and the Empirical”
http://www.esoteric.msu.edu/VolumeIV/astrology.htm
[3] J. Tester, "History of Western Astrology"
http://books.google.com/books?id=L0HSvH96alIC&dq=History+of+Western+Astrology+tester+book&printsec=frontcover&source=bn&hl=is&ei=YNAXSuepFYfUjAegy-XkDA&sa=X&oi=book_result&ct=result&resnum=4
[4] Augustus
http://en.wikipedia.org/wiki/Augustus
[5] Marcus Manilius, "Astronomica"
http://fathom.lib.uchicago.edu/1/777777122543/
[6] Robert Harry van Gent. "The Constellations and the Fixed Stars"
"Hellenistic astrological tables and horoscopes indicate that the sidereal zodiac was employed up to the end of the 5th century AD. The use of a sidereal zodiac was continued by many astrologers of the Hellenistic and Roman Period."
http://www.phys.uu.nl/~vgent/babylon/babybibl_fixedstars.htm
[7] Western sidereal astrology, an interview with Kenneth Bowser
http://www.westernsiderealastrology.com/articles/MountainAstrologerInterview.pdf
[8] Hindu wisdom: India and Egypt
http://www.hinduwisdom.info/India_and_Egypt.htm