1628 BCE, and later.
There are two great stories in the Western tradition that stand somewhere between legend and history: The Flight from Egypt and the Trojan War. Both have been scholarly battlegrounds, dismissed as pure invention by some, accepted as at least partly historical by others. In the case of the exodus story, a great many archeologists nowadays are strong skeptics. Here I summarize what I think is the best argument for the other side.
Barbara Sivertsen, in her book The Parting of the Sea, argues that the exodus story combines oral traditions arising from two different flights from Egypt. First, she suggests that some of the story reflects events around the time of a huge volcanic explosion, the largest in the last five thousand years, which destroyed most of the island of Thera (= Santorini) in 1628 BCE. Most of the Biblical plagues fit what would have been expected in northern Egypt at the time (and in the right time sequence). A tsunami reaching the Nile delta would have contaminated water, and caused fish to die off. Frogs would have been driven from the water. Caustic ash would have stung human skin (in later recountings, “stinging like gnats” was remembered as “stinging gnats”). Insects affected by ash would have sought shelter in people’s houses. Livestock outdoors would have died from breathing ash, and humans and livestock would have developed blisters. Eventually dust in the atmosphere would have precipitated hailstorms. The arrival of the heaviest part of the dust cloud would have shrouded the land in darkness. (Locusts, however, don’t fit the volcano story, and may be an embellishment or a coincidental plague.) All these developments would have precipitated a panicked flight from Egypt on the part of Israelites, led by Moses. (Lower Egypt at the time was ruled by charioteer Hyksos invaders.) According to the archeological evidence, the Wadi Tumilat, an oasis/caravanserai east of the Nile commonly identified as the Biblical Land of Goshen, is abandoned at this time and left uninhabited for centuries.
Other authors have suggested that the Thera eruption had some role in the exodus, but Sivertsen thinks there was also a later flight. In the mid-1400s, Egypt had a significant population of prisoners of war employed as slaves at Tell el-Da’ba, a naval base on the Mediterranean. In Sivertsen’s account, a wave of deaths of Egyptian children led Pharaoh Tuthmose III, frightened of the Israelite god, to expel a group of Israelite slaves. The pharaoh changed his mind, however, and sent an army in pursuit of the slaves along the northern shore of the Sinai. We know that in the mid-1400s, another volcanic eruption, on the Aegean island of Yalli, sent a tsunami around the shores of the eastern Mediterranean. This tsumani caught up with the Egyptian army, but missed Israelites camped further inland. The event was spectacular enough to be melded with the earlier exodus story.
A major reason for skepticism about the exodus story is that it has been very hard to find evidence for the Israelite conquest of Canaan in the fourteenth or thirteenth century BCE, which is when many accounts place the exodus. But if we follow Sivertsen in putting the first exodus much earlier, and allow that the “forty years” in the wilderness was really eighty years, then there is plenty of evidence for massive invasion and destruction of cities in Canaan in the mid 1500s, at the end of the Middle Bronze Age. Israelites could have been among the invaders of Canaan. Around 1550 BCE, the city of Jericho suffered an earthquake that knocked down some of the city walls. The city then burned to the ground, and was largely abandoned subsequently.
We saw earlier on Logarithmic History that oral history can preserve detailed memories of natural catastrophes for long periods of time. At the same time information about numbers and absolute dates mostly gets lost. It will be interesting to see how Sivertsen’s work holds up in the face of further discoveries.