Ancient calendars and the birth of Alexander the Great

In the previous post I proposed a possible birth chart for Alexander the Great who, I deduced, was most likely born on August 19th or 20th of 356 BC in Pella, Greece.   In fact, a sunrise chart for 20 Aug 0356 BC works quite well for the major events in his life.

This investigation led to some interesting facts about ancient calendar systems and the timing of the Olympics, which have caused confusion about the date of Alexander’s birth for many centuries.  This post is essentially a continuation of the last one.

The date I arrived at is at variance with the one given in many textbooks that tend to state that Alexander was born on the 6th day of the ancient Greek month of Hekatombaion, which probably corresponds to 20 July 356 BC.  There is no consensus, however, about how to correlate the ancient Greek calendar with the modern one, partly because intercalary months were added to make the soli-lunar calendar match the seasons of the year (see reference #1 below).  The year began with the first new moon after the summer solstice.  In 356 BC, the first new moon occurred at 6:55 PM LMT on July 14th, so scholars add 6 and come up with a date of July 20th for Alexander’s birth.  They ignore the fact that it was the summer of the Olympic games, which occur every four years, so that since the last Olympics one or two intercalary months would have been added, making Hekatombaion start in August or September rather than July.  Lunar months are 29.53 days long, so 29.53 (perhaps rounded to 30) would have to be added to July 20th to get a more likely date of Alexander’s birth.  This implies that he was born about August 19th (July 20th plus 30) or possibly September 18th or 19th.

Modern scholars uniformly date Alexander’s birth to 356 BC, yet some of the older astrological charts in the literature give his birth year as 357 or 355 BC.  How could this happen?  Most likely because the AD/BC system invented under the auspices of the Catholic Church does not have a year numbered zero.  It goes directly from 1 BC to 1 AD without an intervening zero.  Astronomical years in use today include a zero-year, so it is possible to be a year off in BC dates if you mistakenly go from 1 AD to 0 AD (which does not exist) to 1 BC.  It seems like it should be a 2-year span but there is only one year difference between 1 BC and 1 AD.  Counting this period as 2 years could account for astrological charts of past centuries giving Alexander’s date of birth as 357 or 355 instead of 356 BC.

The next question to arise was how the starting of the Olympic games was timed.  Sources differ on this question.  The source I quoted in the previous post said that the Olympic games were scheduled to coincide with the mid-summer full moon, which meant that the Olympics were typically held in August.  Yet historical records show that the Olympics sometimes took place in July or September, that is, during the first or third months of summer rather than the middle one.  This prompted me to do some searching in scholarly journals and I found the following:

(1) In

The Journal of Philology, Volume 24 

edited by William George Clark, John Eyton Bickersteth Mayor, William Aldis Wright, Ingram Bywater, Henry Jackson on p. 82:

Date of the start of the Olympics

Date of the start of the Olympics

So this author says to count 1308 days from New Moon following the the winter solstice after the last Olympics to get the date of the new one.  The winter solstice four years before the 356 BC Olympics occurred on Dec 25, 360 BC, and the first new moon following it took place on January 22, 359 BC at 8:44 AM.  Adding 1308 to Jan 22nd of 359 BC, I get Aug 22, 356 BC as the date for the next Olympics after 360 BC.   Using this method, Alexander could not have been born in July but must have been born in August around the start of the Olympics.  In other words, he was born within a few days of August 18th or September 20th of 356 BC, depending on when the month of Hekatombaion fell that year, which in turn depends on whether one or two months was inserted since the last Olympics.  A July date does not match the historical records.

If he were born in September, the new moon occurred on September 11, 356 BC, at 8:02 pm.  Most likely the first day of Hekatombaion would have been September 12th in the modern calendar and the 6th day would have been September 17th of 356 BC, which could be an alternative date for Alexander’s birth.  Here is the sunrise chart for September 17, 356 BC.  It also has a Scorpio Moon, like the August 20th chart which I think is more likely (see previous post):

Sunrise 17 Sep 356 BC chart for Alexander the Great.  I think 19 or 20 August is more likely.  Both charts have a Scorpio Moon.

Sunrise 17 Sep 356 BC chart for Alexander the Great. I think 19 or 20 August is more likely. Both charts have a Scorpio Moon.

(2) In

The Easter Computus and the Origins of the Christian Era

By Alden A. Mosshammer, p. 15:


Here the author states that the Olympics began at the full moon in the 8th month following the winter solstice.  The winter solstice prior to Alexander’s birth occurred on 26 Dec 357 BC.  The first new moon after the winter solstice occurred on 19 Jan 356 BC.  The eighth month after the winter solstice began on 13 Aug 356 BC (new moon).  The moon became visible on 14 August 356 BC, and the 6th day of the month would have been 19 or 20 August in our modern calendar.  Historical records report that Alexander was born on the sixth day of the month.   The full moon of the eighth month following the winter solstice took place on 28 August 356 BC, and Alexander was born close to this date.

(3) In

Julius Africanus und Die Christliche Weltchronik: Julius Africanus und Die …

edited by Martin Wallraff, p. 89:

Dating the olympics

Dating the Olympics

This reference is consistent with reference (2) above.

If the Olympics were scheduled during the eighth lunar month after the winter solstice, then we can calculate a range of possible dates during which the Olympics could be held.

The winter solstice generally falls on 25 December.  Each lunar month is about 29.53 days, thus the eighth lunar month would begin at the earliest 207 days after the solstice and at the latest 236 days after the solstice, that is, during the period from 20 July to 19 August.  Because the Olympics are held at the full moon, they would typically be held about 14 days later, that is between 3 August and 2 September every four years.  This method of reckoning the Olympics suggests that Alexander was born in the month of August as suggested in my previous post.  Because it was a soli-lunar calendar, months had to be added every few years to keep pace with the seasons.  The addition of a month may have shifted the start of the Olympics into July or September, but most often it fell in August.  Below is the 20 August chart, which I think is the most likely chart for Alexander’s birth:

Alexander the Great, probably born 20 Aug 356 BC just before the summer Olympics.

Alexander the Great, probably born 20 Aug 356 BC just before the summer Olympics.


About Anthony Louis

Author of books about astrology and tarot, including TAROT PLAIN AND SIMPLE, HORARY ASTROLOGY, and THE ART OF FORECASTING WITH SOLAR RETURNS.
This entry was posted in Astrology and tagged , , . Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s