The Bible’s genealogies allow us to established with certainty that the exodus occurred at the end of the XIII century b.C.. We can more precisely fix the date of the Exodus by making full use of the frequent and numerous references in the Bible itself.
In the 13th century B.C. Egypt was ruled by only two Pharaohs: Rameses II, who reigned for no less than sixty-six years, and his son Merenphthah, who held the throne for a further ten years. The last rulers of the 19th Dynasty were quite insignificant, reigning for very short periods over an Egypt which was in total chaos. This makes the task to identify the rulers mentioned in Exodus sure and simple, since the Bible refers only to two. The first used the Jews as an unskilled labor force to help build the cities of Pithom and Pi-Ramses. This same Pharaoh persecuted Moses, forcing him to flee to the Sinai where he found refuge with Jethro the Midianite. There seems no doubt that he was Ramses II; and in any case this conclusion is consistent with a long and well-founded tradition.
We read in Exodus 2,23 that following the death of the Pharaoh who had persecuted him (i.e. Ramses), Moses returned to Egypt and together with Aaron began at once to organize the flight of the Israelites from Egypt. Because of its general complexity and slow pace of establishing the necessary contacts, the organisation of the whole enterprise must have required a period of not less than two or three years. The Jews took forty-four days (Num. 33,3; Ex. 19,1) to go from Pi-Ramses to Mount Sinai and remained there for just less than one year (Num. 10,11).
A few weeks after their departure from Sinai, as soon as Joshua had returned from his reconnaissance mission in Palestine, the Jews suffered a serious defeat at the hands of the Canaanites near Kadesh-Barnea (Num. 14,15; Deut. 1,44). By an extraordinary coincidence, there is a similar historical account in the "Stele of Israel", so-called because for the first time in history the name "Israel" appears. In this stele Merenptah, Ramses’ successor, celebrates victories gained over the Libyans, who, in the fourth year of his reign had invaded the Nile Delta. On the same stele there is a list of victories over rebel populations in Palestine, which then was still part of the Egyptian Empire. Merenptah almost certainly never left Egypt and, therefore, these victories were clearly gained by his generals or by populations subject to him, such as the Canaanites. The victory over Israel occurred before the end of the fifth year of Merenptah’s reign; since the Jews had left Egypt less than fifteen months before this, the Exodus must have started between the second and the fourth year of Merenptah’s reign.
Let’s then open a book of ancient History and find out when Ramses and Merenptah reigned. Unfortunately, we find different dates for Ramses' death. The Egyptians counted the years separately for each pharaoh, thus we know that a certain event happened in such year of a such pharaoh, but normally we are not able to link this year to an absolute date, unless there are references to some astronomical event that can be dated with precision. For what concerns Ramses II, scholars are undecided between two precise dates: his coronation must have happened either on 1304, either on 1279 b.C.. The calculations have been made on the base of a sequence of lunar months, listed in the Leiden papyrus, concerning the 52nd year of Ramses. That sequence recurs every 25 years and in the XIII century b.C. it occurred on 1278, 1253, 1228 and 1203. The first and the last can be disregarded, being not compatible with the Egyptian chronology; Ramses II died 15 years later, therefore either on 1238, or on 1213 b.C..
There is a difference of 25 years among these. We cannot ignore a third date, the 1224 b.C., that the Cambridge’s school proposes as possible, even if not really probable. It is important to note that the exact date of Ramses' death is one of these three and not any intermediate year among the twenty-five. The Exodus of the Jews from Egypt, therefore, must have taken place in one of the following periods: either in 1236/1234, or in 1222/1218 or even in 1210/1208 B.C. The calculations made on the basis of David's genealogy would tend to favour the last of these three figures; but in any case the difference is not so great as to exclude the other two.
Let’s find out which is the correct one. We only need to make a reasonable hypothesis
All the so-called plagues refer more or less to extraordinary events that really occurred, but which in some cases are highly exaggerated. Such was the case with the hailstorm (Ex. 9,24-32).
The question is how can we interpret the "thick darkness in all the land of Egypt for three days ...(but all the children of Israel had light in their dwellings)” (Es. 10, 22-23). The most plausible explanation, the one that seems to be the most sensible, is an eclipse of the sun. This is an event which is quite extraordinary, but not sufficiently so to be defined as a "plague;” to become so, the duration would have to be prolonged to an extreme. In fact it became three days, where "three" is clearly a period of indeterminate length.
The eclipse occurred when the sun and moon were in conjunction, that is, during a new moon. Since this was after the seventh plague, which occurred at the beginning of April, it must have been the new moon immediately preceding the one that started the first year of Exodus. This puts the time frame at the end of April, or in the first half of May.
The interesting thing about eclipses is that the dates can be calculated exactly, even those in very remote history. Therefore, we need only ascertain if in Egypt, in what was most probably the time of the Exodus, there was actually an eclipse of the sun, and then calculate the exact day. The Jews crossed the Red Sea two months later.
On October 2006 NASA published a “Five Millennium Canon of Solar Eclipses: –1999 to +3000 (2000 BCE to 3000 CE)” ( NASA/TP–2006–214141--October 2006
Fred Espenak and Jean Meeus).
Five solar eclipses occur in Egypt during the time frame we are interested in (see following pictures).
For each eclipse an orthographic projection map of Earth shows the path of the Moon’s shadows with respect to the continental coastlines. The dotted lines delineate the locus of all points where the local magnitude at maximum eclipse is equal to 0.5.
Underneath the maps, the maximum possible error in longitude is indicated, due to the fact that the secular variations of Earth’s speed of rotation are not known with absolute precision. At the most for these eclipses it can be of 4.7°, which means that the actual path could had been shifted right or left for no more than 4.7°.
To the top right are the dates of the eclipses. A few essential remarks need to be made, in order to understand the correct meaning of those dates:
1) All eclipse dates from 1582 Oct 15 onwards use the modern Gregorian calendar currently found throughout most of the world. For eclipse dates prior to 1582 Oct 04 the older Julian calendar is used.
2) The Julian calendar does not include the year 0, so the year 1 BC is followed by the year 1 a.D. This is awkward for arithmetic calculations. In this publication, dates are counted using the astronomical numbering system which recognizes the year 0. We have to take into account the numerical difference of one year between astronomical dates and b.C. dates. Thus, the year 0 corresponds to 1 BC, and the year –100 corresponds to 101 BC, etc., and the historical dates of the 5 eclipses of the maps are respectively: 1236, 1223, 1218, 1211 and 1208 b.C.
3) A further consideration is important in our case, where the relation between the date of the eclipses and the solstices is relevant. Under this respect the Julian and the Gregorian calendars coincide only for the period around the Nicea’s Council, on 325 a.D. (pope Gregory XIII’s reform was set up to reproduce the astronomical situation at the time of that Council, when the rules for the calculation of the Christian Easter were agreed).
When Jules Cesar, on 45 b.C., started the calendar named after him, the summer and winter solstices fell respectively on 24 June and 25 December, three days later than in the Gregorian calendar, due to the fact that the Julian year is a little bit longer than the Gregorian. As we go back in time, the delay gradually increases to reach 12 days at the exodus’ epoch.
We have therefore the following equivalence between the astronomical dates of our eclipses and the actual dates:
astronomical date historical date day of the Gregorian calendar
1. - 1235 May 26 26 May 1236 b.C. 14 May
2. - 1222 Mar 05 5 March 1223 b.C. 21 February
3. - 1217 Jun 05 5 June 1218 b.C. 24 May
4. - 1210 Jul 18 18 July 1211 b.C. 06 July
5. - 1207 May 16 16 May 1208 b.C. 04 May
All five these dates fall within the time period we are considering. If Ramses II died the 1st of September, as it appears probable, Merenptah ascended the throne at least three months later, when his father was definitely buried. The Egyptians used to count the years of a pharaoh starting from the year following the death of his predecessor, including into it the months from the death to the end of the year.
For our calculations, then, we have to assume that the first year of Merenptah started in June of 1237, or 1223 or 1212 b.C. The account of the ten plagues should provide sufficient indications to decide which is the correct date among these three.
The 7th plague, the hail, we said, occurred not before the beginning of April, therefore excluding the eclipse of the 5 March 1223. The eclipse of 5 June 1218 is too late; if it was the correct one, in fact, the Jews would have been defeated on September 1217, at the beginning of the 7th year of Merenptah, well after the stele of the 5th year was engraved. The eclipse of 18 July 1211 b.C. is not compliant with the indications of the Bible, which place Passover in June, while in this case it should recur in August.
Only two dates, then, are left fitting with both, the indications of the Bible and of the stele: 26 May 1236 and 16 May 1208 b.C.. According to the first the exodus should have started in June 1236, at the beginning of the second year of Merenptah, while the second would make it start in June 1208, at the beginning of the fourth year.
Both dates fit with the indications of the Bible and the archaeological evidence, because in both cases the defeat of Israel would have happened well in time to be reported on the Stele of the 5th year of Merenptah. There are, however, a few points that make us decidedly incline for the second. First, the organization of such a complex operation like the exodus of an entire population required time. Communications were slow. Moses had to be informed, in the Sinai desert, that Ramses was dead and that he was no more “wanted” (and this could have happened only after Merenptah replaced the previous officials in Pi-Ramses). He had to come back to Egypt, meet the chiefs of the Jewish tribes and convince them to put their lives and their properties at stake in the risky adventure he was proposing. They had to agree a plan, to sell real estates, provide the logistics for a long trip in the desert and so on. It’s highly improbable that all of this could have happened in only one year.
Second, from the map of the 1236 eclipse, we can clearly see that Egypt was only marginally interested; there are indeed good probabilities that it was not at all touched. On 1208, instead, the eclipse in Egypt had certainly a magnitude more than 80%, and the light of the day was almost completely darkened for several minutes.
Third, with this date the exodus of the Jews would have started three and a half years after Ramses II’s death, a reasonable time for its organisation. Fourth, the calculations based on the genealogies of David, Samuel and Saul are consistent with the later date. Finally, we have to consider that most Egyptologists agree that the most probable date for the death of Ramses II is 1213 b.C.
Everything, therefore, combines in a convincing way with the theory that the ninth “plague” of the Bible, the darkness, was the exaggerated account of the solar eclipse that obscured Egypt on 16 May 1208 b. C. (corresponding to today’s 5th of May).
The Jews left Pi-Ramses the “15th day of the first month” of the Egyptian natural lunar calendar. The beginning of the first month was coincident with the new moon immediately following the eclipse, that is on 15 June 1208 b.C. (corresponding to today’s 4th of June). The exodus, then, started on 30 June 1208 (19 of today), with the full moon, and 14 days later, during the new moon, the Jews crossed the Red Sea. It was the night between the 14 and 15 of July of 1208 b.C. (2/3 July of today), one of the most important dates in human history.
Thirty days later, “the first day of the third month” (Ex. 19.1), that is the 13 August 1208 (corresponding to today’s 2nd august) b.C., the Jews set camp at the feet of the Holy Mountain.
The second year of exodus started the 3 June 1207 (23 May greg), the very day Moses raised for the first time the Tabernacle (Ex. 40, 20).
On 23 July 1207 b.C. (today’s 12 July), the “20th day of the second month of the second year” (Nm. 10,11), the Jews left the Holy Mountain, never to come back again. This is the last date that we can calculate with precision on the base of the biblical account.