History of the Zodiac

Some 10,000 years ago, humanity underwent a step-change in its cultural evolution as it transitioned from a nomadic hunter-gather existence into settlements founded on agriculture. This development would eventually spread around the world and might help explain why, in a historical context, there is often a common ‘theme’ underpinning religious belief based on Sun worship, which might be anchored to the primal belief that the Sun was the ‘bringer of life’ on which the agricultural revolution was so dependent.

 Note: If we were to pick a fairly arbitrary figure of 100,000 years for the migration of homo-sapiens out of Africa and equate a human generation to 20 years, then 5,000 generations of humanity have existed in that time. In comparison, only 500 generations would have existing in the 10,000 years since the start of the agricultural revolution alluded to above. Therefore, in general terms, some 4,500 generations of humanity existed even before the earliest recorded history, such that we might only surmise what these people believed about the ‘meaning of life’ and passed to their descendants.

If we try to put ourselves in the position of those who lived 500 generations ago, we might realise that any stories about the creation of life passed to them by even earlier generations might naturally be considered in terms of the ‘bringer of life’, i.e. the Sun. Of course, today, most might readily accept that anybody directing a question about the ‘ meaning of life’ towards the Sun, as a physical body in the solar system rather than as a deity, would probably not have received a direct answer, although this probably did not exclude some form of answer of being constructed by those asking this sort of question. It is known that the idea of some form of a Sun-god, or Sun Goddess, has been found throughout most of recorded history in various forms and across multiple cultures – see ‘List of Sun Gods . Of course, given the span of time under consideration, some care is needed in separating what may have only been myth from what might have had some factual basis in history. This may be especially true when considering the many conflicting ‘histories’ associated with ancient Egypt and its many religious deities and semi-deities. For example, the story of ‘Horus’ is often considered to be one of the earliest and most significant ancient Egyptian Sun-gods, which could be a merging of history and myth, where ‘Horus’ may have originally been based on a real person, a pharaoh-king, who was later merged into myth as the name given to the rising sun, along with ‘Ra as the noon sun and 'Osiris' , the god of the dead, associated with the dying or setting sun. In one form or another, these types of sun-god deities were worshipped from the late prehistoric-Egyptian period, i.e. 3100 BCE, until the time of the Ptolemaic Kingdom, i.e. 323-30 BCE. However, as a basic premise, it does not seem unreasonable to assume that many other earlier cultures developed myths surrounding deities that lived in the heavens, which we might now assumed to be allegories based on anthropomorphic characterisations of the Sun, Moon and stars, although possibly originally based on real people in earlier history.

Note: Over a period of many thousands of years, Egyptian civilization developed along the Nile River, which supported the rich soil necessary for growing crops for an expanding population. However, the Egyptians also kept written records using a writing system known as hieroglyphics, which have been preserved on stone, clay and papyrus, although few papyrus documents have survived. From this recorded history, we know that Egypt was an important political and economic power at that time based on its agricultural production and other economic resources, which was supported by wide-reaching trade networks along the Nile, the Red Sea and Near East. This civilisation would have had a complex social structure ruled by successive divine God-king dynasties in which the Horus myth possibly developed over a period of some 3000 years, i.e. 150 generations.

While not necessarily being too accurate with a timeline stretching back some 3000 BCE, we know that various civilisations in the ‘Middle-East region had started to emerge that were becoming increasingly sophisticated in terms of written language and mathematics. As a consequence, these early civilisations started to systematically observe the movement of stars and planets in the sky, not only as an extension of their mythical stories about heavenly Sun-gods, but also because it helped them track the passing seasons, such that the planting of crops could be planned. However, over time, a body of knowledge about the movement of the stars and planets began to be formalised into a system of astrology' that divided the ‘heavens into groups of ‘ constellations ’ that forms the ‘zodiac’. The earliest evidence of a developing constellation map comes from inscriptions on stones and clay tablets found in Mesopotamia , dating back to 3000 BCE, although the wider naming of the constellations probably took place much later between 1300-1000 BCE.

Note: Today, the Babylonians are often credited with the initial development of what is now called astrology, although for more than 2,000 years, astrology and astronomy were the same science. However, while the word ‘zodiac’ is derived from the Greek word meaning ‘circle of animals’ its development can also be traced to ancient Egypt that was subsequently developed further by the Babylonians.

In part, we might consider the earliest development of the zodiac as a response to the big question about the ‘meaning of life’, which might have initially focused religious belief skywards to the various Sun-gods of antiquity. However, aspects of what is now considered to be astrology would also later become the foundation stone of astronomical science in terms of the tracking of celestial bodies relative to the Earth.

Note: Each year, there are two solstices and two equinoxes, which signify a change of season in different ways. The word ‘solstice’ comes from the Latin word ‘sol’ meaning ‘sun’ and ‘sistere’ meaning to ‘make stand’. In this context, a solstice describes the moment that the sun reaches its northern or southern-most point, where the Sun appears stationary at a point in the sky. This event occurs twice a year at the winter and summer solstice, i.e. shortest and longest days of the year. In contrast, the word ‘equinox’ comes from a Latin term meaning ‘equal night’ where there is an equal amount of daylight and darkness, i.e. 12 hours, which also occurs twice a year in the spring and autumn.

So, over time, the tracking of the stars led to the recognition and anticipation of events, which occurred over ever-longer periods of time, such as full moons and eclipses. Within this process, clusters of stars in the night were grouped into constellations that has developed into one of the oldest images in human history, i.e. the cross of the zodiac  reflecting the passage of the sun as it passes through the 12 major constellations over the course of a year. We might recognise that the division in the zodiac also reflects the 12 months of the year, the 4 seasons and the positioning of solstices and equinoxes. However, overlaying this astronomical science was the possibly much older anthropomorphic imaginary, such that these early civilizations did not just track the Sun and stars from a scientific perspective, they also personified the heavens with elaborate religious myths anchored in the belief of a creator, often in the form of a sun-god. In this context, the 12 constellations might be seen as the domain of the Sun-god, where each constellation was also linked to elements of nature at certain times of the year, e.g. Aquarius, the water bearer, was associated the spring rains.

So how might we separate science and myth within the historical development of the zodiac?

The classical map of the sky, with the 48 Greek constellations, is said to have originated from at least two different pre-Greek traditions. One tradition comprised of the 12 signs of the zodiac and is assumed to have developed over the period 3,200-500 BCE. However, there is still much speculation about the origin of the constellations, as they appear to have evolved in-line with various adaptations of religious belief over centuries, although some research now suggests that they were also subject to some ‘scientific’ development in the sense that they created a useful pictorial coordinate system. Today, we might perceive a coordinate system as a set of imaginary lines from which position can be determined, i.e. latitude and longitude. However, it is possible that the zodiac constellations originally performed a similar function in the form of distinct and recognisable patterns in the night-sky, which possibly made it easier to identify groups of stars without the need of instruments. Moreover, today, reverse engineering this evidence points to a time and place in which the idea of a zodiac might have first originated, i.e. approximately 2700 BCE at about 36° north latitude, which can be linked to the early Sumerian civilization from which Babylon inherited much of its science.

Note: While it is traditionally claimed that the earliest reference to the zodiac originates with the Babylonians, the discovery of an ‘observatory’ in Metsamor, predating the Babylonian kingdom by almost 2,000 years changes the timeline of events of the first recorded example of dividing the year into 12 sections. Using an early form of geometry, the inhabitants of Metsamor were able to create both a calendar and surmise the curvature of the Earth. This discovery along with engravings suggesting 'zodiac creatures' has given support to the idea that the earliest forms of the zodiac may have been developed by ancient people living in the Euphrates valley as early as 4000 BCE.

There is also evidence for a Hindu zodiac, and while the names differ from the Greek form, the symbols are essentially identical. For example, ‘dhanu’ means bow and corresponds to Sagittarius, the ‘archer’, while ‘kumbha’ means ‘water-pitcher’ and corresponds to Aquarius, the ‘water-carrier’. As a consequence, it is assumed that there was a possible earlier exchange of cultural influences, which might be traced back before the Greeks linked to trading between the Sumerian and Babylonian cultures and the Indus Valley Culture millennia before the Greeks. There is also a Chinese Zodiac with a cycle of 12 years, rather than 1, where each year is represented by an animal. This difference is possibly correlated to a ‘ Jupiter Year’ as it takes 12 years for Jupiter to complete one orbit of the Sun. The origin of the Chinese zodiac may also be based on the mythological story of Buddha, who is said to have invited all the animals to a race, where only the first twelve would be included in the Zodiac calendar. It is known from pottery artefacts that the animals of the Chinese zodiac were recorded in the Tang Dynasty, i.e. 618-907 CE, but are also seen on much earlier artefacts from the Warring States Period, i.e. 475-221 BCE. However, others have argued that the animals of the Chinese zodiac were brought to China via the Silk Road, the same central Asian trade route that brought the Buddhist belief from India to China. As such, some scholars have argued that the Chinese zodiac predates Buddhism and has origins in early Chinese astronomy that used the 12-year orbit of Jupiter, while others argue that the use of animals in Chinese astrology began with nomadic tribes in ancient China who developed a calendar based on the animals they used to hunt and gather.

So how might we separate earlier astrology from modern-day astronomy?

As a generalisation, while astrology was based on the study of the movements of celestial objects, i.e. it has an astronomical component, it also attempts to predict future events and overlay anthropomorphic characteristics onto various celestial objects. In contrast, modern astronomy is purely the scientific study of the properties, interactions and evolution of physical celestial objects. In astrology, the 12 signs of the zodiac are aligned to various constellations which lay along the path of the Sun over the course of one year, i.e. the time between equinox. In the astronomical context, the Earth orbits the Sun and the line of sight to 1 of the 12 zodiac constellations is blocked by the Sun, where in astrological terms the Sun is described as ‘sitting’ in one of the 12 zodiac signs. However, it has long been known that the timing of each equinox, and solstice, varies as the Earth slowly wobbles on its axis every 26000 years, which today is described in terms of the Earth’s Precession, such that the date of the equinox slowly shifts by about 1 day every 70 years. The effect of this shifting is that the position of the Sun within different constellations has slowly change since the earliest zodiacs were developed. As such, the ages of the zodiac are linked to the Earth’s precession about its axis and linked to the original perception that the Sun had an ecliptic path around the Earth. If we divide the 360o rotation path by the 12, then each of the signs of the zodiac corresponds to 30 o segments within this elliptical path. Today, we know that the Earth's axis is tilted at an angle of approximately 23.5° to the plane of this ecliptic path, which then produces the seasonal variations within each year. The effect of the Earth’s precession on its own axis can also be seen in terms of the ‘ North Star’ where, today, the North Pole is aligned with the fixed star Polaris, although this was not the case 3,000 years ago and by the year 14,000 CE, the North Star will be Vega, not Polaris, as illustrated in the diagram right. While there is evidence that the Earth’s ‘wobble’ and its effects on the timing of equinoxes was known to the ancient Egyptians, the official discovery of this mechanism is often attributed to the Greek astronomer, Hipparchus, who was born sometime around 190 BCE.

Note: In the context of the Zodiac, it was observed that the Sun appears in a slightly earlier position at each subsequent spring equinox, when measured against the fixed stars. Although, 1 day every 70 years may not appear to be an obvious change, it would amount to a shift of nearly 1 month, i.e. 28.57 days, over a period of 2000 years and would ultimately lead to variations in different Zodiac maps.

We might also understand that an ecliptic path, like a circle, has neither a start or end, such that some reference point needs to be established, which might be traced back to a spring equinox possibly over 2000 years ago. At this time, the spring equinox would have occurred when the Sun was in the constellation of Aries, such that the first sign of the zodiac is often described in terms of the ‘age of Aries’ which from the Earth’s precession can be calculated. If we approximate the total time for Earth’s precession on its axis to be 26,000 years, then each ‘age’ of the zodiac would align to 2160 years. If we also make a fairly crude but not necessarily ridiculous alignment for the age of Aries to end in 0CE, then we might list the following zodiac ages over the approximated 10,000 years of recorded human history.

Age Start End BCE/CE
Leo 10800 8640 BCE
Cancer 8640 6480 BCE
Gemini 6480 4320 BCE
Taurus 4320 2160 BCE
Aries 2160 0 BCE-CE
Pisces 0 2160 CE
Aquarius 2160 4320 CE

The purpose of outlining the zodiac ages does not really have that much to do with astronomy but may be more significant in terms of astrology and the more mythical stories associated with these ages. Although these more speculative issues are not really the focus of this discussions, we might still outline some basic history that can be correlated to the ages of the zodiac listed above.

  • The Age of Taurus: 4320-2160 BCE
    While there is little in the way of recorded history that extends much beyond this age, i.e. 4320 BCE, we might reasonably speculate that agriculture was being developed in many regions of the world by this time. By about 3500 BCE, it is also known that people were already settled in the Nile valley and, by 3100 BCE, hieroglyphic scripts was being developed and, by 2700 BCE, the first stone pyramids were being built. These pyramids appear to have both astrological and astronomical significance in their positioning and alignment, which might also reflect a significant development in terms of geometry and mathematics in general. The span of time within the age of Taurus also saw the building of wall cities in Babylon and Sumeria plus the rise of a Chinese civilisation and others possibly too numerous to detail.

  • The Age of Aries: 2160-0 BCE
    Despite the obvious development in the previous age, the age of Aries possibly saw the first large-scale development of civilisations that expanded into the empires of the ancient world, i.e. Chinese, Persian, Greek and finally Roman. Each of these civilizations sought more land and territory by conquering the indigenous peoples of other lands as they expanded outward, such that they would have ‘exported’ their cultural stories and myths to an ever-widening population.

Note: While care in needed in assuming that biblical stories of Judaism always equate to actual history, we might highlight the biblical history of Abraham , who is assumed to have lived around 2000 BCE, i.e. near the start of the age of Aries. Abraham would later become a patriarchal figure in three monotheistic religions, i.e. Judaism, Christianity, and Islam. While it is often assumed that Abraham was born in the city of Ur in Mesopotamia, there are considerable discrepancies in the timeframe indicated above, as with the life of Moses , who is assumed to have lived some 500 years after Abraham. However, at this point, the main purpose of citing these biblical characters is to position the earliest development of monotheistic belief within the historic timeline of other developments.

  • The Age of Pisces: 0-2160 CE
    While, at the start of this age, humanity had not necessarily embraced scientific enlightenment, aspects of the scientific method were beginning to separate astrology from astronomy. We might characterise this transition in the work of Ptolemy called ‘The Almagestwritten between 100-170 CE, who was a Greco-Roman mathematician, astronomer, geographer and astrologer.

Note: While accepting that the timeline for each zodiac age cited above can be subject to many different assumptions – see Astrological Ages for more details, we might possibly see that there may be some inferred alignment between BC and BCE with AD and CE and the biblical story of Jesus . One of the main symbols in earlier Christianity is the ‘sign of the fish’, which some have argued is intended to link the birth of Jesus birth to the new age of Pisces, which in astrology has the symbol of two fish.

Finally, we might make some historic reference to Islamic religion, which might be traced back to the recorded life of Muhammad between 570-632 CE. While many aspects of Islam reject the mythological predictions of astrology, it still embraced those aspects based on the science of astronomy and the earlier work of Ptolemy. In this context, Islam also needed to study the heavens as nomadic-desert tribes often travelled at night, such that knowledge of the constellations might help guide their journeys. Later, as the institutions of Islamic faith developed, Muslims also needed to determine the time of their prayers, the direction of the Kaaba and the correct orientation of mosques. Equally, while possibly not a mainstream aspect of Islamic faith, many continued to believe that the ‘heavens’ might still influence Earthly affairs and even the human condition. So, from the perspective of this very cursory outline of astrology, we might still see how it came to influence the development of various religious belief across the world both in terms of earlier mythical stories, which in many instances were anchored in the astronomy of heavenly constellations.