Astral divination involved encoding the phenomena of
the heavens into omens and associating them with events on
earth. Th us, eclipses were thought to signify that the king
might die if appropriate magical countermeasures were not
invoked. Omens of this sort are also known from about 1700
b.c.e. Given that signs in the heavens are visible to all, it is
not surprising that they were thought to off er comments on
the king, the land, or the state, and not on private individu-
als. Not until the confi gurations of the heavens at the mo-
ment of any individual’s birth could be determined was it
possible for astral divination to enter the private domain to
any great extent.
From the Old Babylonian Period (2000–1600 b.c.e.) to
around 700 b.c.e. no surviving sources can be classifi ed as
“astronomical,” if by this term we mean the prediction or cal-
culation of celestial confi gurations at a given moment. Th ere
are, however, compositions in cuneiform that elaborate nu-
merically on certain idealizations as to the movement of the
heavens. Most famously, one of the 70 tablets of the celestial
omen series known by its opening words as Enūma Anu Ellil
(“When the gods Anu and Ellil.. .”) is devoted exclusively
to the lengths of time for which the moon and sun are vis-
ible throughout the year. Nevertheless, the lengths of time are
derived from assumptions as to the ideal length of the month
(30 days) and of the year (360 days), the ratio of the longest to
the shortest day (2:1, where the reality is closer to 3:2), and so
forth. Th is tablet (number 14) represents a very poor model of
the actual behavior of the heavens, but despite appearances its
purpose was astrological, not astronomical—hence its place in
the great omen series. It provided a set of ideal times against
which the real behavior of the heavens could be compared and
interpreted. In short, if observed reality cohered with the ide-
al, that boded well; otherwise, it boded ill. Compositions such
as Enûma Elishl, the creation epic of the cult of the main god
of Babylon, Marduk, further show that the ideals employed in
celestial divination were those ascribed to the universe as it
was believed to have been when the gods fi rst formed it.
By around 700 b.c.e. astral divination had become a
large industry, with expert scholars employed directly by the
Assyrian kings and the great Marduk temple of Babylon tak-
ing detailed records of successive ominous phenomena. We
are well informed about this period because large numbers
of the scholars’ letters to their kings were discovered in the
ruins of Nineveh. It has been suggested that competition
among scholars for royal favor led them to attempt to predict
forthcoming celestial confi gurations ominous to the king.
Th ey did so by studying the long records of dated ominous
confi gurations, such as eclipses or the heliacal rising (the fi rst
appearance in the east directly before sunrise) of the planets,
and eliciting the intervals at which such confi gurations recur.
Th ere is no reason to assume that astronomy came about be-
cause of a desire to regulate the calendar or for intellectual
interest, as has oft en been assumed in the past.
Relatively rapidly the Assyrian investigators discovered
a characteristic interval between eclipses of the same type,
amounting to 223 months exactly, or 6,585 days and about
8½ hours, on average. Th ere is some evidence of attempts to
model the variation of the interval about that mean as early as
the eighth century b.c.e. In the seventh century b.c.e. scholars
identifi ed intervals, expressed in years, at which the planets ex-
hibit the same phase (such as opposition or heliacal rising) in
more or less the same place on the ecliptic. For example, they
found that Jupiter is in the same phase at the same place in the
sky every 71 years. Th ey also discovered the means by which
the length of the month, very ominous to the Mesopotamians,
could be determined. Th e methods derived depended on sum-
ming the intervals between sunrise and moonrise and sunset
and moonset recorded some 18 or 18½ years earlier. It was only
very recently that the rationale behind these methods became
clear to modern scholars and revealed that the ancients must
have carefully scrutinized their records of such lunisolar inter-
vals in order to extract these periodicities. Truly, bookwork lies
behind the world’s oldest astronomy.
If astronomy was invented to service royal astral divi-
nation, the democratization of deriving interpretations from
the sky led to its fi rst and greatest transformation. Babylon
had become the home of astral science with the demise of As-
syria around 612 b.c.e., but with the arrival of the Persians in
539 b.c.e. it ceased to be a capital. It appears that the schol-
ars who had been making astronomical predictions for their
kings turned to the private market. Where celestial divina-
tion derived interpretations from visible phenomena, private
astrological predictions were based on the calculated loca-
tions of all the planets, be they above or below the horizon, at
a given moment (usually the moment of the subject’s birth).
Th e zodiac was probably invented around 500 b.c.e. as a way
to provide a framework for those calculated locations, and it
is to this time that we should date the earliest private birth
astrology, though the earliest known actual birth chart or
“proto-horosocope” dates to 410 b.c.e.
Calculating planetary locations at a given moment repre-
sented a new challenge for the Babylonian astronomers, one
they met by interpolating between locations of the phases, de-
termined from the database of observations and characteristic
periods. In due course they derived means to calculate plan-
etary locations and the details of eclipses without constant
recourse to the database of observations. Th ese database-in-
dependent methods constitute the high point of cuneiform
astronomy and are found in tablets unearthed in Babylon
and Uruk. Th ey reached their most advanced state around
200 b.c.e. aft er centuries of evolution. Th ereaft er, these won-
derful methods reappear along with zodiacal astrology in the
Egyptian, Greco-Latin, Iranian, and Indian worlds.ASIA AND THE PACIFIC
BY MICHAEL ALLEN HOLMES
Most of the advances in the scientifi c study of the heavens in
ancient eastern Asia were achieved by the people of China,
where astronomical truths were sought largely to refi ne theastronomy: Asia and the Pacific 127