The nine planets appear to move in the celestial sphere with reference to the stellar constellations known as Nakshatra (Stars). There are 27 Nakshatras which are repeated in a Hindu calendar every month. The movement of these bodies with respect to the nakshatras are said to control a person's destiny including his thoughts and deeds, status and prosperity. The importance of Navagraha worship has been stressed by ancient saints and maharishis and references are available in the sacred writings, one of them being the 'Maha Prayaschitha Grantha'. It states that by the worship of Navagrahas, the planets which are in auspicious situations offer increased fruits of benefits for one's actions while the planets which occupy less desirous situations tend to remove the evil effects of a person's karma.

One of the earliest  authors of Indiann astrology, is said to be Pita Maha who  wrote a treatise on astrology called Pita  Maha Siddhant(a). He lived and wrote this  book   about  3,000  BCE.  Five   hundred  years  later,  another author-astrologer named Vashishtth(a) wrote several books on astrology, astronomy and  philosophy. His most  important work, and  one which was
used  as an  authority by  all subsequent  writers on  the subject,  is Vashishtth(a) Siddhant(a),  but he wrote many  other equally erudite and authoritative  texts such  as the  Panch Siddhant(a)  Kosh(a), Soory(a) Siddhant(a),   Nityanand(a),  Brhat   Jatak(a),  Aryabhat,   Mansagari, Ranveer,  and the  Laghu Parashar.  E. M.  Plunkett writes  in his book Ancient Calendars and Constellations: "The opinion of the Greek writers at the beginning of the Christian era may be quoted as showing the high
estimation  in  which  Indian  astronomy  was  held.  In  the  Life  of Appollonius of Tyana, the Greek  philosopher and astrologer, written by Philostratus about 210  CE, the wisdom and learning  of Appollonius are set high above his contemporaries  because he had studied astronomy and astrology with the sages of India." In  a book called You and Your Hand by the late  Count Louis Hamon, known better  as Cheiro, this statement is found: "people who in their  ignorance disdain the wisdom of ancient races forget that the great past of India contained secrets of life and philosophy that following civilizations  could not controvert, but were forced  to accept.  For instance,   it has  been demonstrated  that the ancient Hindus understood the precession  of the equinoxes and made the calculation that it [a complete cycle]  took place once in every 25,870 years.  The   observation  and  mathematical   precision  necessary  to establish such  a theory has been  the wonder and admiration  of modern astronomers.   They,  with   their  modern   knowledge  and  up-to-date instruments, are  still quarrelling among themselves  as to whether the precession, the most important feature  in astronomy, takes place every 25,870  years or  every 24,500   years. The  majority believe  that the Hindus made no mistakes, but how  they arrived at such a calculation is as great a mystery as the origin of life itself."

Notes on Astrology from the Encyclopaedia Britannica

Astrology, type of divination that consists in interpreting the influence of planets and stars on earthly affairs in order to predict or affect the destinies of individuals, groups, or nations. At times regarded as a science, astrology has exerted an extensive or a peripheral influence in many civilizations, both ancient and modern. Astrology has also been defined as a pseudoscience and considered to be diametrically opposed to the theories and findings of modern science.

Astrology originated in Mesopotamia, perhaps in the 3rd millennium BC, but attained its full development in the Western world much later, within the orbit of Greek civilization of the Hellenistic period. It spread to India in its older Mesopotamian form. Islamic culture absorbed it as part of the Greek heritage; and in the Middle Ages, when western Europe was strongly affected by Islamic science, European astrology also felt the influence of the Orient.

The Egyptians also contributed, though less directly, to the rise of astrology. They constructed a calendar, containing 12 months of 30 days each with five days added at the end of the year, that was subsequently taken over by the Greeks as a standard of reference for astronomical observations. In order that the starry sky might serve them as a clock, the Egyptians selected a succession of 36 bright stars whose risings were separated from each other by intervals of 10 days. Each of these stars, called decans by Latin writers, was conceived of as a spirit with power over the period of time for which it served; they later entered the zodiac as subdivisions of its 12 signs.

In pre-Imperial China, the belief in an intelligible cosmic order, comprehended aspects of which would permit inferences on correlated uncomprehended aspects, found expression in correlation charts that juxtaposed natural phenomena with the activities and the fate of man. The transition from this belief to a truly astrological belief in the direct influence of the stars on human affairs was slow, and numerous systems of observation and strains of lore developed. When Western astronomy and astrology became known in China through Arabic influences in Mongol times, their data were also integrated into the Chinese astrological corpus. In the later centuries of Imperial China it was universal practice to have a horoscope cast for each newborn child and at all decisive junctures in life.

Once established in the Classical world, the astrological conception of causation invaded all the sciences, particularly medicine and its allied disciplines. The Stoics, espousing the doctrine of a universal "sympathy" linking the microcosm of man with the macrocosm of nature, found in astrology a virtual map of such a universe.

Greek astrology was slow to be absorbed by the Romans, who had their own native methods of divination, but by the time of Augustus, the art had resumed its original role as a royal prerogative. Attempts to stem its influence on the populace met repeatedly with failure.

Throughout pagan antiquity the words astronomy and astrology had been synonymous; in the first Christian centuries the modern distinction between astronomy, the science of stars, and astrology, the art of divination by the stars, began to appear. As against the omnipotence of the stars, Christianity taught the omnipotence of their Creator. To the determinism of astrology Christianity opposed the freedom of the will. But within these limits the astrological worldview was accepted. To reject it would have been to reject the whole heritage of classical culture, which had assumed an astrological complexion. Even at the centre of Christian history, Persian magi were reported to have followed a celestial omen to the scene of the Nativity.

Although various Christian councils condemned astrology, the belief in the worldview it implies was not seriously shaken. In the late European Middle Ages, a number of universities, among them Paris, Padua, Bologna, and Florence, had chairs of astrology. The revival of ancient studies by the humanists only encouraged this interest, which persisted into the Renaissance and even into the Reformation.

It was the Copernican revolution of the 16th century that dealt the geocentric worldview of astrology its shattering blow. As a popular pastime or superstition, however, astrology continued into modern times to engage the attention of millions of people, this interest being catered to in the 20th century by articles in the daily press, by special almanacs, and by astrology manuals.

Ancient Astral omens:
Egypt, Greece, India, China, and Islam

The evidence for a transmission of lunar omens to Egypt in the Achaemenid period lies primarily in a demotic papyrus based on an original of about 500 BC. A more extensive use of Mesopotamian celestial omens is attested by the fragments of a book written in Greek in the 2nd century BC and claimed as a work addressed to a King Nechepso by the priest Petosiris. From this source, among others, the contents of Enuma Anu Enlil were included in the second book of the Apotelesmatika, or "Work on Astrology" (commonly called the Tetrabiblos, or "Four Books"), by Ptolemy, a Greek astronomer of the 2nd century AD; the first book of an astrological compendium, by Hephaestion of Thebes, a Greco-Egyptian astrologer of the 5th century AD; and the On Signs of John Lydus, a Byzantine bureaucrat of the 6th century. Yet another channel of transmission to the Greeks was through the Magusaeans of Asia Minor, a group of Iranian settlers influenced by Babylonian ideas. Their teachings are preserved in several classical works on natural history, primarily that of Pliny the Elder (c. AD 23-79), and the Geoponica (a late collection of agricultural lore).

In various Middle Eastern languages there also exist many texts dealing with celestial omens, though their sources and the question as to whether they are directly descended from a Mesopotamian tradition or are derived from Greek or Indian intermediaries is yet to be investigated. Of these texts the most important are those ascribed to Hermes Trismegistos by the Harranians and now preserved in Arabic, the Book of the Zodiac of the Mandaeans (a Gnostic sect still existing in Iraq and Khuzistan), the Apocalypse, attributed to the Old Testament prophet Daniel (extant in Greek, Syriac, and Arabic versions), and The Book of the Bee in Syriac.

The transmission of Mesopotamian omen literature to India, including the material in Enuma Anu Enlil, apparently took place in the 5th century BC during the Achaemenid occupation of the Indus Valley. The first traces are found in Buddhist texts of this period, and Buddhist missionaries were instrumental in carrying this material to Central Asia, China, Tibet, Japan, and Southeast Asia. But the most important of the works of this Indian tradition and the oldest extant one in Sanskrit is the earliest version of the as yet unpublished Gargasamhita ("Compositions of Garga") of about the 1st century AD. The original Mesopotamian material was modified so as to fit into the Indian conception of society, including the system of the four castes and the duty of the upper castes to perform the samskaras (sanctifying ceremonies).

There are numerous later compilations of omens in Sanskrit--of which the most notable are the Brhatsamhita, or "Great Composition," of Varahamihira (c. 550), the Jaina Bhadrabahu-samhita, or "Composition of Bhadrabahu" (c. 10th century), and the Parishistas ("Supplements") of the Atharvaveda (perhaps 10th or 11th century)--though these add little to the tradition. But in the works of the 13th century and later, entitled Tajika, there is a massive infusion of the Arabic adaptations of the originally Mesopotamian celestial omens as transmitted through Persian (Tajika) translations. In Tajika the omens are closely connected with general astrology; in the earlier Sanskrit texts their connections with astrology had been primarily in the fields of military and catarchic astrology.

Varahamihira also called VARAHA, or MIHIRA (b. 505, Ujjain, India--d. 587, Ujjain), Indian philosopher, astronomer, and mathematician, author of the Pañca-siddhantika ("Five Treatises"), a compendium of Greek, Egyptian, Roman, and Indian astronomy. Varahamihira's knowledge of Western astronomy was thorough. In five sections, his monumental work progresses through native Indian astronomy and culminates in two treatises on Western astronomy, showing calculations based on Greek and Alexandrian reckoning and even giving complete Ptolemaic mathematical charts and tables. Although Varahamihira's writings give a comprehensive picture of 6th-century India, his real interest lay in astronomy and astrology. He repeatedly emphasized the importance of astrology and wrote many treatises on shakuna (augury) as well as the Brhaj-Jataka ("Great Birth") and the Laghu-Jataka ("Short Birth"), two well-known works on the casting of horoscopes.

 Greek astrology was transmitted to India in the 2nd and 3rd centuries AD by means of several Sanskrit translations, of which the one best known is that made in AD 149/150 by Yavaneshvara and versified as the Yavanajataka by Sphujidhvaja in AD 269/270. The techniques of Indian astrology are thus not surprisingly similar to those of its Hellenistic counterpart. But the techniques were transmitted without their philosophical underpinnings (for which the Indians substituted divine revelation), and the Indians modified the predictions, originally intended to be applied to Greek and Roman society, so that they would be meaningful to them. In particular, they took into account the caste system, the doctrine of metempsychosis (transmigration of souls), the Indian theory of five elements (earth, water, air, fire, and space), and the Indian systems of values.
The Indians also found it useful to make more elaborate the already complex methodology of Hellenistic astrology. They added as significant elements: the naksatras (or lunar mansions); an elaborate system of three categories of yogas (or planetary combinations); dozens of different varieties of dashas (periods of the planets) and antardashas (subperiods); and a complex theory of astakavarga based on continuous horoscopy. The number of subdivisions of the zodiacal signs was increased by the addition of the horas (15⁰ each), the saptamshas (4 2/75 each), and the navamshas (3⁰ 20' each); the number of planets was increased by the addition of the nodes of the Moon (the points of intersection of the lunar orbit with the ecliptic), and of a series of upagrahas, or imaginary planets. Several elements of Hellenistic astrology and its Sasanian offshoot (see below In Sasanian Iran), however--including the lots, the prorogator, the Lord of the Year, the triplicities, and astrological history--were introduced into India only in the 13th century through the Tajika texts. Besides genethlialogy, the Indians particularly cultivated military astrology and a form of catarchic astrology termed muhurta-shastra and, to a lesser extent, iatromathematics and interrogatory astrology.

Shortly after Ardashir I founded the Sasanian Empire in AD 226, a substantial transmission of both Greek and Indian astrology to Iran took place. There were Pahlavi (Iranian language) translations of Dorotheus of Sidon, Vettius Valens, Hermes, and an Indian called (in the Arabic sources) Farmasp. Since the Pahlavi originals are all lost, these translations provided the only knowledge of the Sasanian science. Genethlialogy in Iran was essentially an imitation of the Hellenistic (though without any philosophy), onto which were grafted some Indian features, such as the navamshas and a Shaivite interpretation of illustrations of the Greco-Egyptian deities of the decans. The most influential and characteristic innovation of the Sasanian astrologers was the development of the theory of astrological history--that is, the writing of history, both past and future, on the basis of extensions of the techniques of the prorogator, the Lord of the Year, the planetary periods, and the continuous horoscopy employed in Hellenistic genethlialogy. This was done in conjunction with Zoroastrian millenarianism (the division of the finite duration of the material creation into 12 millennia).
Astrology entered Islamic civilization in the 8th and 9th centuries in three simultaneous streams--Hellenistic, Indian, and Sasanian. Arabic translations from the Greek and Syriac represented the Hellenistic science, from Sanskrit the Indian version, and from Pahlavi the Sasanian combination of the two. But to these influences Islamic astrology, through the work of Abu Ma'shar, an astrologer of the 9th century, added the Harranian adaptation of the Neoplatonic definition of the mode of astral influences in terms of Aristotelian physics. Abu Ma'shar further elaborated Sasanian astrological history and greatly expanded the number of lots that an astrologer had to take into consideration. Much attention was paid by the Muslims to catarchic and interrogatory astrology, but, under attack by the theologians for denying divine intervention in the world and man's free will, astrology rapidly declined in its appeal to Muslim intellectuals after the Mongol invasions of the 13th century, though not before its influence had spread in India, the Latin West, and Byzantium.
During the last upsurge of paganism in the 5th and 6th centuries AD, Byzantium (the Eastern Roman Empire) boasted a host of astrologers: Hephaestion, Julian of Laodicea, "Proclus," Rhetorius, and John Lydus. Though their works are singularly unoriginal compilations, they remain the major sources for an understanding of earlier Hellenistic astrology. By the end of the 6th century, however, the general decline of the Byzantine Empire's intellectual life and the strong opposition of the church had combined to virtually obliterate astrology, though some practice of reading celestial omens survived in Byzantium as it did in western Europe. The science was revived only in the late 8th century and the 9th century under the impact of translations from Syriac and Arabic. The period from about 800 to 1200 was the most propitious for Byzantine astrology, though nothing was essentially added to astrological theories or techniques. This period was rivaled only by a last flowering of astrology in the late 14th century, when John Abramius and his students revised the older astrological treatises in Greek to provide the Renaissance with vulgate texts.

The astrological texts of the Roman Empire were written almost universally in Greek rather than in Latin; the only surviving exceptions are the poem Astronomica of Manilius (c. AD 15-20), the Matheseos libri ("Books on Astrology") of Firmicus Maternus (c. 335), and the anonymous Liber Hermetis ("Book of Hermes") from the 6th century. In the absence of astronomical tables in Latin, however, none of these was of any use, and astrology for all practical purposes disappeared with the knowledge of Greek in western Europe. It was revived only with the numerous translations of Arabic astrological and astronomical treatises executed in Spain and Sicily in the 12th and 13th centuries, supplemented by a few translations directly from the Greek. But the new astrology in the Latin-reading world remained essentially an offshoot of Islamic astrology, gaining an adequate representation of its Hellenistic originals only in the 15th and 16th centuries. These two centuries also witnessed the fullest flowering of astrology in western Europe, frequently in conjunction with Neoplatonism and Hermetism. By the 17th century, however--with the displacement of the Earth from the centre of the universe in the new astronomy of Copernicus (1473-1543), Galileo (1564-1642), and Johannes Kepler (1571-1630), and with the rise of the new mechanistic physics of Descartes (1596-1650) and Newton (1643-1727)--astrology lost its intellectual viability and became increasingly recognized as scientifically untenable. Though Kepler attempted to devise a new method of computing astrological influences in the heliocentric (Sun-centred) universe, he did not succeed.
 
Bibliography: Astrology

Indian Sources

  Anga Vidya by Vaharahamihira. Kadalangudi House 1978. A work dealing with omens and the
like.
  Astrological Primer by Rao. Astrological Office, 1973.
  Bhargava Nadika. Madras GOS. 1949. A small Sanskrit work outlining the principal effects of
planetary periods.
  Bhavartha Ratnakara tr Raman, Raman Pubs, 1974. An English language translation of a work
on predictive astrology.
  Bhrigu Samhita. MSS in India Office Library.
  Daivajnabharanam. Madras Government Oriental Series, 1951-1956. An important Sanskrit
compilation of the Kerala school covering predictive astrology.
  Deha Dhatu Vijnanam by Dr.A.L.Pathi. Shri Dhanvantari Press, Bezwada, nd. Brief but
interesting English book on Ayurveda.
  Devakeralam Chandrakala Nadi. Madras Government Oriental Series, 3 volumes. 1950-1956.
Sanskrit fragments of what must have once been a much larger work.
  Goladipika by Parameshvara. Adyar Library Series No.22, nd. English translation of a text on
astronomy.
  Graha & Bhava Balas by Raman, Raman Pubs, 1970. English book on the strengths of planets
and houses.
  Hindu Predictive Astrology by Gopesh Kumar Ohja, Taraporevala, Bombay, 1972. Probably
the most readable English introduction to Indian astrology.
  Horasastra by Varahamihira. Adyar Library 1950. Sanskrit text of Varahamihira's classic work.
  Kaulajnana Nirnaya of Siddha Matsyendranath, translated by Michael Magee, Prachya
Prakashan, 1978. Source work on Kaula and Nath yoga including much material on 21600.
  Manual of Hindu Astrology by Raman. IBH Prakashana, 10th edition, 1976.
  Navagraha by Sarasvathy & Ardhanareeswaran, Kadalangudi No.1, 1978. Symbolism of the
Hindu 9 planets (Rahu and Ketu - the nodes of the Moon - are included).
  Rashigola Sphutaniti of Acyuta. Adyar Series No.29, 1955. English translation of astronomical
text.
  Sangita Ratnakara. Adyar Library Series, nd. The classic Sanskrit text on music with an English
translation of the first chapter including much information on yoga and the like.
  Saptarishinadi. Volumes 1-6, Madras Government Oriental Series, 1951-1956.
  Shri Kalachakratantra-Raja ed Banerjee. The source text of Tibetan Kalachakra.
  Siddhanta Darpanam by Nilakantha Somayajin. Adyar Series No.30, nd. Astronomical text.
  Vamakeshvara Tantra tr Magee, Prachya Prakashan 1986. Source work on Shri Vidya.
  Yavana Jataka ed & tr by Pingree, Harvard UP, 1978. An indispensable translation of a work
preceding the Brihad Jataka.

Western Sources

  American Sidereal Ephemeris 1901-2000 published by Astro Computing Services.
  Astrological Origins by Cyril Fagan. Llewellyn Publications, 1974.
  Bhavanopanishad ed & tr Lokanath, Sothis Weirdglow 1982.
  Cosmic Influences on Human Behaviour by Michel Gauquelin, Futura, 1974.
  Primer of Sidereal Astrology by Cyril Fagan. Littlejohn, 1971.
  Shri Yantra and Sidereal Astrology by Shri Lokanath, Sothis Magazine 1974.
  Sidereal Calculation Tables compiled by Mary Austin,Moray Series, 1961.
  Solar and Lunar Returns by Donald Bradley, Llewellyn 1974.
  Solunars Handbook by Cyril Fagan. Clancy Publications, 1976.
  Spheres of Destiny by Michel Gauquelin, Corgi, 1981.
  Stahl's Solunar Ephemeris, privately printed, 1964 and 1965.
  The Parallax Problem by Donald Bradley, Llewellyn 1974.
  Zodiacs Old and New by Cyril Fagan, Anscombe 1951.