Climate and Collapse

The Late Bronze Age did not die a slow, lingering death. It came to a swift end in the 12th century B.C.E., marked by sudden cultural collapse and widespread population shifts. Out of the ashes of the Bronze Age destructions emerged classical Greek culture and biblical Israel. When one considers the contributions these two cultures have made to Western civilization, it becomes clear that the change from the Bronze to the Iron Age in the eastern Mediterranean represents one of the most momentous revolutions in human history.

Could climate also have played a part in the 12th-century B.C.E. collapse of Late Bronze Age societies? I think so. And it is in the context of the tumultuous events taking place throughout the eastern Mediterranean world that the emergence of Israel in Canaan should be understood.

The extent of the social dislocations and cultural discontinuities at the end of the Late Bronze Age is little short of astounding. They extend to almost all the civilizations of the ancient world. We can only briefly survey them.

In southern Greece during the 13th century B.C.E., Greek-speaking Mycenaean rulers, usually living in fortified palaces, used extensive bureaucracies to control politics, religion, local economies and many other aspects of everyday life. Mycenaeans (or Achaeans as they are sometimes called) also seem to have ruled over Crete at this time. They had settlements on Paros, on Rhodes and at Miletus in Asia Minor. Their trade goods were in demand throughout the eastern Mediterranean.

But peace did not accompany prosperity. Many Mycenaean rulers, including those at Gla, Athens and Tiryns, as well as at Mycenae, found it necessary to enlarge or strengthen their fortification walls during the 13th century B.C.E. After all, it was during that century that the palaces of Knossos in Crete and Thebes in Boeotia were destroyed.¹ Then came the widespread disasters of the late 13th and early 12th centuries B.C.E. Boeotian Thebes was burned again, along with dynastic centers at Gla, Iolkos, Araxos, Krisa, Menelaion, Pylos, Tiryns and Mycenae. Some sites were abandoned for centuries; others, permanently. Population shifts were immense. Refugees settled in Attica, in Achaea, on the Ionian Islands and on the far-off island of Cyprus, as well as in an unfortified town between Tiryns and the coast. Meanwhile, areas of Thessaly, Boeotia and parts of the Peloponnese, which formerly had contained many settlements, became depopulated. The population of Greece seems to have declined by as much as 75 percent. The level of material culture declined sharply, and the cultural unity of the Mycenaean Age came to an end. The highly centralized Mycenaean palaces and their elaborate bureaucracies disappeared, and small, poor agricultural villages replaced them.²

The situation was much the same in Crete. The population declined and the material culture became much poorer. People abandoned the previously well-populated coastal areas (especially in southern Crete) and built new villages in the hills or in other easily defensible positions.³

In Asia Minor the great Hittite Empire collapsed at the end of the 13th and early 12th centuries B.C.E. Vassals rebelled in western Anatolia and elsewhere. There was sporadic fighting with the Kaska people of northern Asia Minor. These conflicts were accompanied by crop failures and famine in parts of the kingdom. In about 1212 B.C.E., during the reign of Pharaoh Merneptah, the Egyptians sent a large shipment of grain to a alleviate hunger in Hittite lands.⁴ And about a generation later, among the last letters received by the king of Ugarit, on the Mediterranean coast of modern Syria, before the city was destroyed, were three that mention famine in Hatti. In one of these letters, the last Hittite king, Suppiluliumas II, appealed to his Ugaritic vassal to send immediately 2000 measures of grain to Cilicia because it was a matter of life or death.⁵

Early in the 12th century B.C.E. the Hittite records became silent. Hattusas, the capital city, was violently destroyed, along with Troy, Miletus, Tarsus, Alaca Hüyük, Alisar, Carchemish, Alalakh, Ugarit, Qatna, Qadesh and other cities that had been part of the Hittite Empire.

Hittite culture did not totally disappear, though. In Syria during the 12th century B.C.E., a number of small kingdoms arose whose rulers bore Hittite names and whose religious, literary, artistic and epigraphic traditions derived from those of the Hittite Empire. The Assyrians called these kingdoms “Hatti,” the old name for the Hittite Empire. But the language of these “Neo-Hittites” was not the Hittite of the former rulers of Hattusas. It was a dialect of Luwian, a related Indo-European language that had been spoken by some groups in the western provinces of the Hittite Empire during the Bronze Age. Obviously, people from western Asia Minor migrated to Syria during the upheaval accompanying the fall of the Hittite Empire, and there they tried to preserve many of the Hittite traditions under which their ancestors had lived.”⁶

Around 1160 B.C.E. an Anatolian army of Muski (possibly the people the Classical Greeks called the Phrygians) invaded some of the northwestern provinces of Assyria. About 50 years later the Assyrian king Tiglath-Pileser I defeated a large combined army of Muski and Kaska people in the same area.⁷ The Kaska had inhabited an area just south of the Black Sea during the era of the Hittite Empire, and the Muski seem to have come from east central Asia Minor. Assyrian records thus provide additional evidence of 12th-century migrations from Asia Minor into Syria and northwestern Mesopotamia.

Throughout much of central Asia Minor, the heartland of the Hittites, there is little evidence of new settlements or new peoples for about a century after the collapse of the Hittite Empire. Possibly the population returned to seminomadism. As in Greece, however, it is likely that the area suffered serious population losses.

The same kinds of things were happening in Assyria and Babylonia. By the late 14th and early 13th centuries B.C.E., Assyria had grown into a major power. It had begun to put pressure on the eastern frontiers of the Hittite Empire and to expand into eastern Syria. But toward the end of the reign of Tukulti-Ninurta I (c. 1244–1208 B.C.E.) Assyria went into rapid decline, as military campaigns ceased and revolts broke out. Assyria was not able to recover from her internal problems and renew her expansion until the second half of the tenth century B.C.E. Rival Babylon was unable to take much advantage of this period of Assyrian weakness, for she too was having problems with internal rebellion, as well as with raids by Elamites and seminomadic tribes.⁸

The relatively few written sources that exist for this period of turmoil and weakness in Mesopotamia present a gloomy picture. Seminomadic Aramaeans made frequent incursions into Assyrian territory. The Muski and Kaska, mentioned Earlier, also attempted invasion. Several incursions by Elamites are recorded. There is also written evidence of higher-than-normal temperatures, drought, and famine (which in Mesopotamia seems to have continued throughout the 11th century B.C.E.). The Erra Epic, a poetic composition explaining Babylon’s renewed prosperity after this period of crisis, includes characters who personify the troubles besetting Babylonia prior to the ninth century B.C.E.—“scorched (earth)” (Erra), “fiery sun” (Ishum), and “plague” (the Sibitti demons).⁹ An Assyrian letter (c. 1090 B.C.E.) mentions “rains that have been so scanty this year that no harvests were reaped.” An Assyrian chronicle (c. 1082) states that “a famine (so severe) occurred (that) [peop]le ate one another’s flesh.”¹⁰ Drought, famine and hunger are mentioned at least 14 times in texts dating from the 11th and first part of the 10th centuries B.C.E.¹¹

Grain shortages led to higher prices. The usual exchange price for about thirty seahs (approximately two bushels) of barley had been one silver shekel. But in the 11th and early 10th centuries B.C.E., the price for grain rose to between two and four silver shekels. The inflationary peak seems to have been reached in the mid-tenth century B.C.E., when an inscription records that in Babylon a gold shekel would purchase only two seahs of barley.¹² Since one gold shekel was usually worth ten silver shekels, this text indicates that as a result of the grain shortage, prices had risen to 150 times the old price!

Mesopotamia also suffered a significant loss of population in the period just after 1200 B.C.E. Archaeological surveys of southern Mesopotamia indicate that in the old Sumerian heartland just north of the Persian Gulf, population declined by about 25 percent. The situation was worse further north: In the Diyala region the loss in population appears to have been about 75 percent.¹³

Egypt weathered the 12th-century B.C.E. tumult better than most other areas of the eastern Mediterranean. The fabric of Egyptian society and civilization remained essentially intact, in contrast to the almost total collapse that took place in Mycenaean and Hittite lands. But not even Egypt could maintain her former strength and grandeur in the face of the widespread calamities.

In the fifth year of Merneptah’s reign (c. 1208 B.C.E.), Egypt beat back an invading Libyan army that was supplemented by five groups of outsiders (Shardana, Shekelesh, Akawasha, Lukka, and Tursha) described variously as “northerners” or “of the Countries of the Sea.” According to one of Merneptah’s inscriptions (not the famous “Israel Stele”), these invaders were “roaming the land and fighting to fill their bellies daily; they have come to the land of Egypt to seek food for their mouths.”¹⁴

A generation or so later in the fifth year of Ramesses III (c. 1178 B.C.E.), the Libyans attacked Egypt again. This time they were joined by tribes known as the Peleset (Philistines) and Tjeker. Then, in Ramesses III’s eighth year (c. 1175 B.C.E.), a great coalition of land and sea raiders consisting of Peleset, Tjeker, Shekelesh, Denyen, and Weshesh moved through Asia Minor and Syria towards Egypt, destroying as they went. These various tribes of Sea Peoples all seem to have come from the Aegean area and the coastal regions of Asia Minor.¹⁵

The invading force was divided into two groups, one moving overland along the coast, while the other manned a fleet of ships sailing near the shore. Clearly this was no mere raiding party searching for booty. The Egyptian reliefs at Medinet Habu show that the invading army was accompanied by ox-carts containing women and children. Entire tribes of people were on the move.

Ramesses III defeated the land force in a battle fought somewhere in Lebanon or northern Palestine. However, the Sea Peoples’ fleet continued on to Egypt itself, where it seems to have been overwhelmed in one of the branches of the Nile. Egypt was saved, but she had been severely weakened. Soon after the death of Ramesses III, Egyptian control over Palestine and southern Syria ended and Sea Peoples settled at Dor and other coastal sites.

Other indications of hardship and trouble appear from records of the Nile Valley region during the 12th century B.C.E. From the reign of Ramesses III (c. 1182–1151 B.C.E.) through that of Ramesses VII (c. 1133–1127 B.C.E.), the price of emmer wheat in Egypt gradually rose to a level eight (or, for a time, 24) times higher than its earlier rate. It remained at a high level for the rest of the century. Only in the time of Ramesses X (c. 1108–1098 B.C.E.) did the price drop, but even then it remained twice what it had been at the beginning of the 12th century B.C.E.¹⁶ During this period the government also had problems paying the generous grain and other food rations owed to the elite artisans who cut and decorated the royal tombs in the hills opposite Thebes. The craftsmen staged strikes at least six times between Ramesses III’s 29th regnal year (c. 1154 B.C.E.) and the third year of Ramesses X (c. 1106 B.C.E.) because their grain allotments were months in arrears.¹⁷

Grain shortages and inflation encouraged other evils as well. Corruption among public officials was rampant. Royal tombs were robbed. Banditry and civil war destabilized society. Several times during the latter half of the 12th century B.C.E., marauding groups of Egyptians and Libyan and Meshwesh mercenaries terrorized the area around Thebes, looting and killing, on one occasion destroying an entire town. Anarchy broke out in Thebes. The temples of Amun were looted.¹⁸ By the time Ramesses XI died (c. 1070 B.C.E.) and the 20th Dynasty ended, Upper Egypt was ruled by an army commander of Libyan descent. The era of Egyptian greatness was over.

All too often, specialists have concentrated on a limited, rather narrow view of these events, providing a variety of disparate, ad hoc explanations for the chaos and destruction in various parts of the ancient world at this time. Barbarian invasions from the North, the Israelite invasion of Canaan, the loss of trade, overly centralized economies, the collapse of governing systems, peasant revolutions against the ruling classes—all of these been suggested as causes of collapse in one part or another of the eastern Mediterranean. The latest theory traces the Great Kingdoms’ downfall to changes in warfare that shifted power from chariot forces to infantry.¹⁹ But such widespread conflict, destruction of cities, population movements, crop failures, depopulation and cultural collapse must have an equally broad explanation. That these various disturbances were unrelated is extremely doubtful.

None of the offered explanations mentioned is comprehensive enough to explain all of the evidence, especially the grain shortages in the Hittite Empire, Mesopotamia, and Egypt. And if all these problems (peasant revolts, overspecialized economy, attacks by barbarian hordes and so forth) in different areas are unrelated, why did they happen at about the same time? Why, after a long period of stability, did Bronze Age civilization collapse? Some broader, more comprehensive explanation is needed.

Almost thirty years ago Rhys Carpenter suggested that the end of the Late Bronze Age in the eastern Mediterranean was due to a climatic change.²⁰ Although his theory attracted some support,²¹ it has been rejected by most archaeologists an historians because they erroneously believe that there is no evidence for it; it is, they argue, mere speculation. In the past two decades, however, an increasing body of evidence indicates that there probably was a climatic change in the area between approximately 1300 and 1000/950 B.C.E.

Analysis of American and European tree-ring sequences covering the past 7,000 years shows that there was a change in the northern hemisphere’s climate between about 1300 and 1000 B.C.E.²² This evidence is confirmed by many other indicators of prehistoric climates in Europe—levels of various lakes, movements of glaciers, and changes in peat bogs.²³ This European evidence points to a warmer, drier period starting around 1400 or 1300 B.C.E. and lasting until about 900 B.C.E.^a Since there is a very close correlation between moisture trends in Europe and those in the Near East, such evidence can be applied beyond Europe itself.

Other evidence shows that glaciers in the Himalayan and Karakorum mountain ranges of Asia began retreating around 1200–1150 B.C.E. and that the monsoon rains in the Indus Valley were considerably below normal at that time.²⁴

The most persuasive data comes from the eastern Mediterranean itself. A log unearthed at Gordion in Asia Minor had a series of very narrow tree-rings from around 1200 B.C.E., indicating a period of extremely dry years at that time.²⁵ These dry years came at about the same time that Pharaoh Merneptah’s Hittite allies pleaded with him to send them grain “to keep alive the land of Kheta [Hatti].”²⁶

Studies of past levels of the sources of the Nile indicate that the river’s levels dropped considerably after 1300 B.C.E., reaching their lowest point around 1200 B.C.E. and staying at that low level until about 1100 B.C.E.²⁷ Because of the reduced discharge of the Pelusiac branch of the Nile, its mouth silted up and the capital city of Pi-Ramesses had to be abandoned soon after 1100 B.C.E.²⁸ During the reign of Ramesses X (c. 1108–1098 B.C.E.), Lower Nubia, the area just south of the first cataract, became dessicated because of the Nile’s abnormally low levels.²⁹

Other paleoenvironmental data, such as water levels and sedimentation rates, provide additional evidence. P.A. Kay and D.L. Johnson have estimated the stream flow of the Tigris and Euphrates rivers over a period of 6,000 years. They do this by studying sediment samples from Lake Van and the Persian Gulf, pollen samples from various areas in Mesopotamia, barley-harvest dates and other data. They found that after about 1250 B.C.E., the stream flow of the Tigris and Euphrates dropped rapidly, reaching its lowest point around 1150 B.C.E. In the years just after about 950 B.C.E., the stream flow rapidly rose to high levels once more.³⁰

A study of wood charcoal from archaeological sites just north of the Negev in Israel indicates that at the end of the Late Bronze Age there was a change from Mediterranean to Saharan vegetation. This change in vegetation seems to indicate a shift from a relatively moist climate to a much drier one.³¹ While the study made no allowance for the possible importation of wood from other regions, wood imports into this area were probably not very extensive.³²

When these various indications of a shift to a warmer (and, in the Near East, a drier) climate around the 13th–12th centuries B.C.E. are combined with the textual references to large-scale migrations, grain shortages and famine, plus the archaeological evidence of widespread destruction and population decline in various areas, it seems extremely likely that a change in the area’s climate took place and that it precipitated the widespread disturbances at the end of the Bronze Age. While the weather patterns may have varied somewhat from year to year, the trend in the eastern Mediterranean for at least a century and a half (c. 1300–1150 B.C.E.) was toward drier conditions than had prevailed in preceding centuries. The result was a long drought in many areas at the end of the 13th and early part of the 12th centuries B.C.E. The dry weather seems to have moderated a bit in most regions during the latter half of the 12th century B.C.E. and ended in the tenth century B.C.E. when cooler, moister weather resumed.

It was the growing long-term drought that probably set in motion a series of chain reactions leading to internal strife, warfare, plague, piracy, population movements, destruction of cities, decline in population, inflation, loss of trade and systems collapse that weakened or destroyed the Late Bronze Age civilizations of the eastern Mediterranean. The drought and the tumult it set off were probably not only largely responsible for the destruction of many cities throughout the area, but also for the creation in Canaan of detached groups of seminomads, refugee peasant farmers and occasional bands of brigands who fled into the central hill country.

The dry weather seems to have abated somewhat between 1150 an 1100 B.C.E., allowing most of the marauders and refugees to settle down once again. At that time the Canaanite hill-country frontier zone would have been especially attractive to surviving groups of refugees. Few settlers were there to contest the occupation by new villagers, and rough hill country was less likely to be invaded by the Philistines and other Sea Peoples who had settled on the coast, or by the remaining Canaanite nobles who were contending for the most desirable areas. In the hills, groups of these refugees seem to have joined together into tribes which in turn formed a confederation that called itself Israel.³³

Lest I be charged with advocating an environmental determinism, let me be clear. Not all or even most historical events are heavily influenced by environmental factors. But some are! Ancient agricultural societies were extremely vulnerable to even minor changes in climate, especially in the eastern Mediterranean where in the best of times much of the land is desert too arid for farming or grazing.

The evidence for a climatic change around 1300–1000 B.C.E. seems to be the best explanation to account for all the various kinds of data we now have. But it is not yet conclusive. I agree with critics who say that more evidence is needed. One hopes that in the future, humanists and social scientists will collaborate more closely with climatologists and other environmental scientists when studying historical periods, as well as prehistoric periods. Together we will be able to develop better research strategies for determining the climatic and environmental conditions in past ages. Perhaps when more evidence is in, we will be able to determine with greater certainty whether a climatic change precipitated the catastrophes at the end of the Late Bronze Age out of which, among other societies, ancient Israel emerged.

The Late Bronze Age did not die a slow, lingering death. It came to a swift end in the 12th century B.C.E., marked by sudden cultural collapse and widespread population shifts. Out of the ashes of the Bronze Age destructions emerged classical Greek culture and biblical Israel. When one considers the contributions these two cultures have made to Western civilization, it becomes clear that the change from the Bronze to the Iron Age in the eastern Mediterranean represents one of the most momentous revolutions in human history. Could climate also have played a part in the 12th-century B.C.E. collapse of […]