The Palermo
Stone of the 5th Dynasty (from about 2400 BC.) is the only major document
which originates from the period preceding the 12th Dynasty, but it
is only a fragment of a large slab. A fragmented papyrus of the 19th
Dynasty (about 1300 BC.), known as the Turin Royal Canon, gives a complete
list of the kings of Dynasties I-VIII, which seem to cover a period
of about 955 years.
The important
point is that none of these documents can by themselves provide any
absolute dates for early Egyptian history since they are not linked
to our modern era of dating or to any other system which can be connected
to our system.
The use
of astronomical calculations to decipher references to this Sothic cycle
in ancient Egyptian records forms the foundation of all ancient chronology.
Censorinus says:
"The
moon is not relevant to the "great year" of the Egyptians
which we call the "Year of the Dog" in Greek and the "Year
of the Little-Dog" in Latin, because it begins when the constellation
or star "Little-Dog" [allegedly the modern Canis Major or
Sirius] rises on the first day of the month which the Egyptians call
"Thouth". For their civil year has only 365 days without
any intercalation. Thus a quadrennium among them is about one day shorter
than the natural quadrennium, thus it is 1461 years before this "year"
returns to the same beginning point. This "year" is called
"heliacal" by some and "the divine year" by others."
(Censorinus, De Die Natali, ch. 18, my translation)
Censorinus'
statement certainly is not exhaustive. It gives us little information
about how this "great year" was used or when it came into
use. It is certainly open to debate how applicable this description
of the Egyptian calendar and astronomy is to the 2 nd and 3 rd millennia
BC. It does not address the issue of changes in the nature of the
Egyptian calendar which may have occurred over the millennia. We have
no definite proof that the Egyptians were aware of dating long eras
by the Sothic cycle in the 2 nd millennium BC. Even if we grant that
they did, we have no certain knowledge of the date when any Sothic cycle
began.
Most historians
presently accept the claim that Censorinus places the beginning of a
Sothic cycle in about 140 AD and by extension in 1320 BC, 2780 BC and
perhaps 4240 B.C. Censorinus says:
"As
among us so also among the Egyptians a number of "eras" are
referred to in their literature, such as that which they call "of
Nabonnasar" which began from the first year of his reign, which
was 986 years ago. Another is called "of Philip" which is
counted from the death of Alexander the Great which was 562 years ago.
But the beginning of these is always from the first day of the month
which the Egyptians call Thoth, which this year fell on the 7 th day
before the Calends of July [June 25], 100 years ago when Emperor Antoninus
Pius was consul for the second time, and Bruttius Praesens was the other
consul, the same day fell on the 12 th [corrected to the 13 th ] day
before the Calends of August [July 21, corrected to July 20] at which
time the "Little-Dog" usually rises in Egypt. Therefore it
is possible to know that of that great year, which as I wrote above
is called "solar" or "of the Little-Dog" or the
"divine year," now the hundredth year has passed. I have
noted the beginnings of these years lest anyone think that they begin
from January 1 or some other time, since the starting points chosen
by the originators of these years are no less diverse than the opinions
of philosophers. For that reason the natural year is said to begin
by some at the new sun, that is the winter solstice, by others at
the summer solstice, by others at the vernal equinox and by others at
the autumnal equinox, by some at the rising of the Pleides and by some
at their setting, by many at the rising of "the Dog." (Censorinus,
Ch. 21, My translation)."
Again
it is noteworthy how little Censorinus actually says and how much is
deduced from his statement. Censorinus is writing not to establish
a system of chronology, but to discuss various dates for New Years Day
in different cultures. He gives no specific date as the starting point
for a Sothic Cycle as he does for the other eras which he mentions.
All he does is give the date of the Julian calendar on which the first
of Thoth fell in the year of his writing, which is well established
as 238 or 239 AD., and one hundred years earlier in 139 AD. In 238
AD the first of Thoth fell on about June 25 Julian. One hundred years
earlier it fell on about July 20, which is the date The Little-Dog (supposedly
Sothis) usually rises in Egypt. He seems to be referring to a conventional
method of dating more than to an actual observation of the rising of
Sothis on that date.
As noted
in the translation above, a textual correction of one day is necessary
to get the rising of Sirius onto the correct calculated date. Censorinus,
makes no direct statement that a new Sothic cycle began then, but his
statement about the passage of one hundred years of the great year and
his indirect reference to the rising of Sothis are interpreted as indications
that a new Sothic cycle began in about 139 AD. It is argued that some
coins of 139 AD also suggest that a new Sothic cycle began then.
Theon,
another late classical writer, explicitly states that a Sothic cycle
began in 26 BC. Now this period of 1460 years, commenced from a certain
time, terminated in the 5th year of the reign of Augustus so, from the
last epoch, the Egyptians begin all over again to find themselves every
year one quarter of a day in advance.
Al Biruni
an Arab chronologist (973-1048), supports Theon. It was Augustus who
caused the people of Alexandria to give up their system of reckoning
by non-intercalated Egyptian years, and to adopt the system of the Chaldeans,
which in our time is used in Egypt. He did this in the sixth year of
his reign; therefore, they took this year as the epoch of this era.
Augustus wanted the Egyptians to intercalate the years, that they might
always agree with the Greeks and the people of Alexandria. Into this
subject, however, it would be necessary to inquire more closely. At
that time precisely five years were wanting till the end of the great
intercalation period. Therefore, he waited till five years of his rule
had elapsed, and then he ordered people to intercalate one day in the
months in every fourth year, in the same way as the Greeks do. Thereupon
they dropped the use of the names of the single days, because, as people
say, those who used and knew them would have been required to invent
a name for the intercalary day.
If Theon
rather than Censorinus is correct, the chronology of early Egypt is
off by 165 years.
Among
recent astronomers the same divergencies exist. Lockyer rejected the
Censorinus date and placed the beginning of Sothic cycles in 270 BC,
1728 BC and 3192 BC. He bases his conclusions on the premise that Censorinus
was in error because he failed to take into account calendric reforms
which Lockyer believed might have occurred about 600 BC. If Lockyer's
theory were correct Egyptian history would be misdated by over 400 years.
Other pioneers of the field, such as Boit, had still different dates.
Lockyer's
theory does not seem to be acceptable, because he calculates the move
of Sothis through the fixed year in the opposite direction from all
other authorities. However, Lockyer does introduce an additional Sothic
date which has a bearing on the Censorinus/Theon controversy. According
to an inscription found at Philae, which can be dated to about 122 BC
the rising of Sirius was 37 days away from Thoth 1. Since Sirius moves
one day every four years, it would take about 148 years for the rising
of Sirius to arrive on Thoth 1. Lockyer counts in the wrong direction
(122+148 = 270 B.C.). However, if we go in the standard direction (148-122=
26 AD.), we get the same date specified by Theon, and thus we have support
for Theon versus Censorinus.
Besides
lack of agreement of the time when a Sothic cycle began, this theory
also faces other uncertainties. It is not certain how long a Sothic
cycle lasts since there are other astronomic variables involved besides
the precise length of the solar year. Calculations of the Sothic cycle
have ranged from 1423 to 1506 years.
We do
not know for sure with which star or constellation Sothis should be
identified for all periods of Egyptian history. It is generally accepted
that Sothis is the star which we call Sirius, although none of the sources
gave any evidence for this from before classical times. Porphry in
De Antro Nym harum says, "Near Cancer is Sothis
which the Greeks call the Dog." Solinus Polyhistor
says that this star rises between July 19-21.
In Chapter
21 of his work, concerning Isis and Osiris, Plutarch says, "The
soul of Isis is called `Dog' by the Greeks and the soul of Horus is
called Orion." Since Sothis is identified with Isis in other
Egyptian texts, and Sirius is called the Dog in Greek, we conclude that
Sothis is the star which we-call Sirius. However there are a number
of difficulties. At least the second half of Plutarch's statement appears
to be in error, because Orion is usually associated with Osiris not
Horus. According to some Egyptologists Egyptian astronomical names
did not always remain attached to the same celestial object. Osiris
was first associated with Venus; later Osiris was associated with Jupiter.
The planet Venus, which was first identified with Osiris, was later
identified with Isis. Sometimes "right eye" is a title of
Isis-Hathor, sometimes it is a title of the sun.
Plutarch
also identifies Osiris with the constellation which the Greeks call
Argo. The hieroglyphic triangle which represents Sothis also appears
to represent the zodiacal light, and the Egyptians apparently knew both
an Isis-Sothis and a Horus-Sothis. The term wp rnpt which refers
to the rising of Sothis, also refers to the beginning of the civil year
and the birthday of the king. Even the Greek word "Sirius"
is not always attached to the same celestial object. Similar shifts
and uncertainties apply to the identification of ancient astronomical
names in general, for example, the constellations in Job.
According
to the English astronomer Poole, Sirius was not on the horizon coincident
with the rising of the sun on the Egyptian New Year's Day in 140 BC,
the date specified by Censorinus and those who follow him. Macnaughton
set up a chronology based on the supposition that Sothis was Spica,
not Sirius, as a way around this difficulty. Canopus and Venus are
other candidates that have been suggested, perhaps less plausibly.
Kenneth Brecher has revived the doubts about identifying the bright
star referred to in records as Sothis/the Dog/Sirius with the star we
call Sirius today. Babylonian and Roman sources as late as Ptolemy
all call "Sirius" a red star. Seneca says it is redder than
Mars. In his star catalog Ptolemy refers to the bright red star in
the face of the Dog. He links Sirius with red stars like Aldebaran
and Arcturus.
The star
which we presently call Sirius is not a red star. No theory of stellar
evolution offers any explanation for how a red star could become white
in 2000 years, although much speculation has centered around possible
changes in the companion star which is part of Sirius. There is a flaw
either in our identification of Sothis as our Sirius, in the ancients'
observations, in our translation of their texts, or in present theories
of stellar evolution, which must be based more on computer analysis
than on observation.
One explanation
which has been offered is that the red color refers to the star only
as observed in heliacal rising near the horizon. Perhaps "red"
simply means "bright" or "beautiful" as it does
in Akkadian or Russian. At any rate, we can say that there is at
least some question about the identification of Sothis as our star Sirius,
and a thorough re-study of the pertinent Egyptian and Greek astronomical
terms would be valuable. Furthermore, the whole concept of dating
by reference to the Sothic cycle is only tenable if we assume that there
were no revisions of the Egyptian calendar between the Hellenistic age
and the time of the Twelfth Dynasty, or that we have an accurate knowledge
of any such changes that did occur. Such changes are especially possible
in the Hyksos period when foreigners controlled Egypt. Two notes
in Manetho's king lists say that two different Hyksos kings introduced
changes from 360 day calendars to 365 day calendars in the time following
the Twelfth Dynasty. Since there is evidence that a 365 year calendar
was in use already in the 5th Dynasty, it is possible that the Hyksos
introduced their own calendar when they took control of Egypt, but then
returned to the superior Egyptian calendar. [Brug, John, Ph.D.;
The Astronomical Dating of Ancient History before 700 AD., 1988]
