How Vedic Astrology Developed

The phrase "Vedic astrology" suggests something very old and unchanging: a body of knowledge handed down from the Vedas, the oldest scriptures of India, and kept intact ever since. The reality is more interesting. The tradition has several layers, laid down in different centuries for different purposes, and each is worth looking at separately. Some are very old. Some are not. And some of the best-known features of the system turn out to have a more complicated history than either its admirers or its critics tend to assume.

The traditional Indian name is jyotisha, from a word meaning "light," and it covers the study of the heavenly bodies, timekeeping and astrology together. "Vedic astrology" is a more recent English label. It points to a genuine connection, because jyotisha is one of the six auxiliary subjects of the Vedas, but as we will see, what that connection meant in the beginning is not what most people mean by astrology now.

The first layer: a calendar for rituals

The earliest jyotisha was concerned with time, not with fate. The Vedic rituals had to be performed on the right days, at the right phase of the Moon, in the right season, and that required a reliable calendar. The Rigveda and the Atharvaveda already refer to the nakshatras, the lunar mansions, the sequence of 27 (sometimes 28) stars or star groups that the Moon passes through in its monthly circuit. They gave the Moon a kind of address in the sky.

The oldest surviving Indian text devoted to this subject is the Vedanga Jyotisha, traditionally credited to a sage called Lagadha, which survives in two versions, a shorter one attached to the Rigveda and a longer one attached to the Yajurveda. It sets out a five-year cycle for the calendar, starting at the winter solstice. It says nothing about the planets and nothing about individual lives. As with the Mesopotamian material in the history of Western astrology, the date of the text is disputed, with estimates ranging from the second millennium BCE to the last centuries BCE, and the same difficulty applies: texts of this period were memorised and recited long before they were written down, so their age is easier to argue about than to prove.

Even at this early stage, one detail connects to later astrology. The Rigveda mentions a demon, Svarbhanu, who swallows the Sun and Moon and causes eclipses. The idea of a "seizer" in the sky is an old one in India, and we will meet it again.

The second layer: omens

A parallel strand of Indian learning read the sky, like the Mesopotamian diviners, for signs. This is the branch sometimes called samhita, concerned with omens and the general fortunes of kings and kingdoms. Its great compendium is the Brihat Samhita of Varahamihira, written in the sixth century CE, which gathers omens of many kinds and cites earlier authorities for them. It is a reminder that the idea of reading the heavens for portents was not a foreign import. It was present in India long before the birth chart arrived.

The third layer: the horoscope arrives

The reading of an individual's birth, the horoscope, appears in Sanskrit much later than the calendar and the omens, and here the evidence points to a meeting with Greek astrology in the early centuries of the common era.

The earliest surviving Sanskrit text on the subject is the Yavanajataka, "the book of the Greeks' nativities." David Pingree argued that it was a Sanskrit verse version of a prose translation made in the second century CE from a Greek text, probably from Alexandria. Historians generally hold that Hellenistic astrology came into India: the twelve signs beginning with Aries, the twelve houses reckoned from the ascendant, and the order of the planets that gives us the days of the week all appear in India in this period. Some of the technical vocabulary was borrowed too. Kendra, the word for the "angular" houses, is widely thought to come from the Greek kentron, "centre," although individual cases are debated, and the origin of the word hora is contested.

Not everyone accepts Pingree's picture. Bill Mak, working from a manuscript discovered in 2011, argues that the Yavanajataka is later than Pingree thought, from the fourth to the sixth century CE, and that it contains more Indian and specifically Vedic material than Pingree allowed. On Mak's view the text was a blend of Greek and Indian astral science from the start. The question of how much of Indian horoscopy is foreign and how much is native remains genuinely open.

A telling figure from this period is Varahamihira, who worked at Ujjain in the sixth century CE (the usual dates are 505 to 587, though they are not certain). His Pancasiddhantika summarises five systems of astronomy, ranking them by accuracy. Two, the Paulisa and Romaka siddhantas, show clear Greek influence, and his writings contain about thirty-five Sanskritised Greek astronomical terms. He praised the Greeks as well trained in the sciences, though he judged them impure in ritual matters. He also wrote the Brihat Jataka, a major text on horoscopy. Here is an Indian astrologer comfortably working with Greek material and making it his own.

On the older question of timekeeping, scholars disagree about the direction of influence. Pingree suggested that some of the early calendar science came from Mesopotamia. Yukio Ohashi rejected that and argued that it developed from observation in India. Kim Plofker considers independent development plausible, partly because the loanwords one would expect to find on either side are missing.

The classical synthesis

From the seventh century or so, Indian astrology developed into a system with its own character. The great compendium, the Brihat Parashara Hora Shastra, is traditionally attributed to the sage Parashara, but most scholars treat the text as composite, with layers added between roughly the seventh and eleventh centuries CE. A work called the Saravali, by Kalyana Varma, dates from around 800 CE.

Several features of this system are distinctive, and it helps to know what they are.

The sidereal zodiac. Vedic astrology measures the zodiac against the fixed stars, while the Western tropical zodiac is anchored to the seasons, with 0° of Aries fixed at the March equinox. Because the Earth's axis slowly wobbles (a drift called precession, about one degree every seventy-two years), the two have slid apart. The gap, called the ayanamsa, is now about twenty-four degrees. An Indian government committee on calendar reform recommended a standard value in the 1950s, known as the Lahiri ayanamsa, and it is the one most widely used today. The practical result is that your Sun sign in Vedic astrology is usually the sign before your Western one.

The nakshatras. The lunar mansions of the Vedic period stayed at the centre of the system. Each of the 27 covers 13°20′ of the zodiac, and each is divided into four quarters. In Vedic astrology the Moon's nakshatra at birth is a core piece of information.

The dashas. These are periods of life ruled in turn by different planets. The most widely used system, the Vimshottari dasha, runs on a 120-year cycle, and where you start in it depends on the Moon's position among the nakshatras at your birth.

Rahu and Ketu. The two lunar nodes, the points where the Moon's path crosses the Sun's, are treated as shadowy planets. Rahu means "the seizer." The ancient story of the eclipse demon is told in several places in the epics and Puranas: a demon drinks some of the nectar of immortality and is beheaded, so that his head and body live on as Rahu and Ketu and periodically swallow the Sun and Moon. This is the same figure as the Vedic Svarbhanu, and it gives a mythic home to a concept that the Greeks and later European astrologers also had, as the Dragon's Head and Tail.

The houses and yogas. Houses are counted from the rising sign, the lagna, in twelve equal divisions. Astrologers also look for named combinations of planets, called yogas, such as those associated with power or wealth.

What is settled, and what isn't

It may help to put the picture in order.

Reasonably well established:

• Indian astronomy and timekeeping have Vedic roots, with the lunar mansions and a ritual calendar among the oldest elements.
• The earliest Vedic jyotisha concerned the calendar, not planets or horoscopes.
• A tradition of reading the sky for omens existed in India alongside this.
• Greek horoscopic astrology came into India in the early centuries CE, and Indian astrologers such as Varahamihira worked closely with it.
• The mature system, with its sidereal zodiac, nakshatras, dashas and nodes, took shape in the first millennium CE.

Still debated:

• The age of the Vedanga Jyotisha and the other early texts.
• How much of Indian horoscopy came from Greece and how much developed in India.
• The dates and authorship of the Yavanajataka and the Brihat Parashara Hora Shastra.
• The direction of influence in early timekeeping.

You will often see claims that Vedic astrology is five thousand years old or more. Figures like that come from tradition, and not from texts that can be dated. That does not make the tradition less valuable. It means that when we say "Vedic astrology," we are naming a tradition with deep roots and a long, documented development, whose most distinctive features were assembled over many centuries, in conversation with the astrology of the Mediterranean world, and in a form that is unmistakably its own.