By Pat Lowinger
The societies of the Late Bronze Age were as advanced as they were diverse. Surrounding the eastern Mediterranean, these vibrant civilizations in Anatolia, Greece, Egypt and the Levant have left a mysterious fingerprint upon history. At the end of the 12th century BCE, the civilizations associated with these cultures largely disappeared, leaving only ruins as testaments of their near-forgotten greatness. This disappearance, commonly referred to as ‘The Collapse’ has long been the object of academic debate and archaeological research.  Were these civilizations destroyed by drought or earthquakes, migrations or raids by nomadic seafarers, or did the very fabric of their civilizations somehow unravel? While evidence exists to support one or more of these theories within certain regions or societies each ultimately fails to offer a definitive explanation which can be broadly applied to the entire region. By accepting a multi-causation approach historians can better understand the totality of events, both natural and man-made, which interacted in various degrees to extinguish the light of these highly advanced Bronze Aged civilizations.
Drought and Famine
Drought is often offered as a causal factor for the The Collapse and is supported by a fair amount of archaeological evidence in certain instances. Drought Theory is largely credited to Rhys Carpenter who first offered it as wholesale explanation for The Collapse in Greece, Anatolia and the Levant. Agriculture in the Late Bronze Age relied heavily upon rain; necessary for production of grain crops and grazing lands for livestock. Long periods of drought greatly effected the production of food, resulting in underproduction and eventually famine. Without food, ancient peoples were forced to abandon the population centers and relocate to areas with more ample resources. Within just a few years, severe drought could reduce even the largest Bronze Age civilizations to mere ghost-towns. 
There is clear evidence that the Hittites of the Later Bronze Age suffered from long-term famine within their empire. Beginning as early as the reign of Ramses II Hittite emissaries requested consignments of grain to be shipped by sea from Egypt to Anatolia (c. 1230 BC).  There appears to have been numerous instances in which the Hittites either themselves or through intermediaries, such as the Kingdom of Ugarit, purchased grain supplies from Egypt. “More specific mention of famine conditions provides stronger evidence, such as the demand by the Hittite Queen during the reign of Rameses II that the dowry for a Hittite princess be expedited because her country has no grain, and the request” was “a matter of life and death.”  Subsequent analysis of tree-rings (fossilized) from the same time period show strong indications of long-term drought.  So it is clear that in some or all regions of Anatolia that famine was widespread and long-term.
Yet, while famine may explain some or all of what led to the demise of the Hittites, what is equally obvious is that in the case of Egypt that their own agricultural resources were bountiful enough not only to provide for their own sustenance but also significant enough to provide some relief to the peoples of Anatolia. Like Egypt, there is little or no evidence to support Drought Theory in the Mycenaean kingdoms of Greece, “At many of the Greek sites destroyed in the Catastrophe there is in fact evidence that the arsonists must have been looking for something other than food.”  Among the fire damaged ruins were found burnt stores of wheat, barley, olives and grapes which strongly indicate food was not the key motivation for the attacks and that substantive supplies of food existed. 
The Human Factor
Drought, famine and economic collapse can only go so far to explain the fate which befell the civilizations of the Late Bronze Age. The last key piece of the puzzle is the ‘human factor’. Namely warfare and the advances in technology that characteristically usher differing tactics onto the battlefield- often to the extreme detriment of enemy. Pioneered by Robert Drews and referred to as Military Explanation, this theory offers that it was in fact advances in four key pieces of Bronze Age military technology which led to The Collapse.  These were the longsword, round shield, torso armor and javelin (long range).
Prior to the longsword, known among weapon typologists as the Naue II sword, the key weapon(s) among Later Bronze Age warriors were the spear and the bow. The spear being the primary weapon for foot infantry and the composite bow the primary ranged weapon of chariot armies of Egypt, Anatolia and the Levant.   These ‘chariot armies’ relied upon formations of bow-armed charioteers who would attack the enemy at range, they retreat before retaliation could be made. The large bodies of infantry served primarily as a counter-punch to be utilized when the enemy’s infantry had been disrupted or scattered by the elite chariot formations.  The Naue II, commonly known as the Mycenaean sword, was effective in both thrusting and slashing attacks, which could easy defeat the large, bulky wicker and hide shields commonly used by infantry during the chariot army era.  When the Mycenaean sword was combined with the smaller, round and stronger shield; the result was a swordsman who could move quickly and engage in brutal close melee with an enemy.
To add even more protection to the swordsman, the use of torso armor became more widespread. As depicted in the Mycenaean ‘Warrior-Vase’ of 12th century BC Mycenae; each warrior wears a torso armor, most likely constructed of an early form of leather padding adding greatly to the individual protection provided to each warrior.  The net result was a warrior who relied more on the effectiveness of his own skill and personal protection and much less on the combined shield formation(s) so characteristic in warfare of the Later Bronze Age.
Last, but far from least, is the rather simple javelin. Constructed from elm or ashwood and topped with a bronze spearhead, this weapon was devastating in its effects against mounted opponents.  With an effective range of 30-40 meters, the javelin no longer allowed chariot-borne archers to escape retribution. And the retribution was all too deadly; even if the archer or charioteer was not hit by the missile, a wounded horse or horses either bolted or could no longer be effectively controlled. This quickly led to the chariot’s crew being swarmed by the enemy. While not conclusive in itself, Mycenaean warriors of the post-palatial period are typically pictured carrying one to two javelins or ‘short’ throwing spears. 
Whether a single or a series of several causal factor(s), the System Collapse Theory offers a few key insights which should not be overlooked in any analysis of The Collapse. Simply stated in broad terms, it states that civilizations of the Late Bronze Age suffered numerous instances of plague, famine and wars which resulted in the eventual failure of these societies and abandonment of population centers.  Some modifications to the base theory include raids by ‘the Sea People’ or geological factors (earthquakes) which further compounded the turmoil caused by other previously stated factors. 
While often criticized for being overly broad, the real strength of the System Collapse Theory is the incorporation of many causal factors of which socioeconomic is preeminent and migration to be rather limited.  A key feature of the theory is reliance upon evaluation of several possible factors and viewing them as a cause-effect multiplier.  When combined with archaeological evidence of pressures induced by raids of the ubiquitous ‘Sea Peoples’- present in both the Linear B tablets of Pylos and the Great Karnak Inscription at Luxor a strong and academically reasonable argument materializes. In effect, when combined with one or more natural disasters (earthquake, famine or flood), the Human Factor further pressured the weakened civilizations of the Later Bronze Age to the point of general collapse.
It is quite possible that there will never be an entirely conclusive understanding of what led to the end of the great Bronze Age Civilizations in the last hours of the 12th century BCE. What is evident, and I believe can be demonstrated are various causes, with varying degrees of influence ultimately led to the The Collapse. By way of illustration, the evidence is clear of widespread drought and famine in Anatolia which likely marked the beginning of the demise of the Hittite Empire. Yet even drought alone does not fully answer the question. We know in the decades prior to the Hittite collapse that the death of King Muwatalli fueled a power struggle for succession between the king’s brother and son.  The legacy of the Hittites clearly demonstrate that advocacy for a single causal factor for The Collapse, simply does not hold water or survive analytical scrutiny.
By the way of further comparison, I believe there is little or no evidence to support the widespread application of Drought Theory. As previously stated, neither Greece nor Egypt suffered from prolonged periods of drought. What is clear is various Mycenaean Citadels were destructed by fire, clearly indicating raiding and/or conquest. The real question regarding the Mycenaeans was whether this threat was foreign (again the mysterious ‘Sea Peoples’) or from other Mycenaeans or both.
What is clear and uniquely featured in each of these regions is the demise of the ‘Chariot Army’. Even though the chariot would remain in use, it would be largely ceremonial or religious, a throwback to times since past. Infantry weapons had evolved and eclipsed the chariot as the premier weapon of war, leading to the defeat of these great armies by invaders. Whether these defeats themselves spelled the doom of Greece and Egypt are debatable but it appears that when combined with other factors, such as socioeconomic, plagues, famine or geological factors, the evidence for a multi-causation is strong. This leaves the multi-causation approach to understanding what led the end of the Late Bronze Age civilizations is the most valid and academically sound model currently available to historians.
References & Citations:
Brouwers, Josho. Henchmen of Ares: Warriors and Warfare in Early Greece. Rotterdam: Karwansaray Publishers, 2013.
Bryce, Trevor, and Adam Hook. Hittite Warrior. Oxford: Osprey, 2007.
Byrd, William. Bronze Javelin Head. Mercer University. Accessed March 24, 2015. http://libraries.mercer.edu/repository/handle/10898/386.
Cline, Eric. The Oxford Handbook of The Bronze Age Aegean. New York. Oxford University Press, 2010.
Demand, Nancy H. The Mediterranean Context of Early Greek History. Chichester, U.K.: Wiley-Blackwell, 2011.
Drews, Robert. The End of the Bronze Age: Changes in Warfare and the Catastrophe Ca. 1200 B.C. Princeton, NJ: Princeton University Press, 1993.
Fields, Nic, and Brian Delf. Bronze Age War Chariots. Oxford: Osprey, 2006.
Healy, Mark, and Angus McBride. New Kingdom Egypt. London: Osprey Military, 1992.
Hartzler, Bruce. Warrior Vase. Mycenae. Accessed March 04, 2015. http://hartzler.org/cc307/mycenaean/index.html.
Roosevelt, Christopher H. The Archaeology of Lydia, from Gyges to Alexander. Cambridge: Cambridge University Press, 2009.
Spalinger, Anthony John. War in Ancient Egypt: The New Kingdom. Malden, MA: Blackwell Pub., 2005.
 Drews, Robert. The End of the Bronze Age: Changes in Warfare and the Catastrophe Ca. 1200 B.C. Princeton, NJ: (Princeton University Press 1993), 34.
 Demand, Nancy H. The Mediterranean Context of Early Greek History. (Chichester, U.K.: Wiley-Blackwell 2011), 196-197.
[3 &4] ibid., 195.
 ibid., 195-196.
 Drews, The End of the Bronze Age: Changes in Warfare and the Catastrophe Ca. 1200 B.C., 84.
 ibid., 83-84.
 ibid., 102-103.
 Fields, Nic, and Brian Delf. Bronze Age War Chariots. (Oxford: Osprey 2006), 38-41.
 Spalinger, Anthony John. War in Ancient Egypt: The New Kingdom. (Malden, MA: Blackwell Pub. 2005), 17-19.
 Healy, Mark, and Angus McBride. New Kingdom Egypt. (London: Osprey Military 1992) 21-24.
 Drews, Robert. The End of the Bronze Age: Changes in Warfare and the Catastrophe Ca. 1200 B.C. Princeton, NJ: (Princeton University Press 1993), 203-204.
 Brouwers, Josho. Henchmen of Ares: Warriors and Warfare in Early Greece. (Rotterdam: Karwansaray Publishers 2013), 35-36.
 Cline, Eric. The Oxford Handbook of The Bronze Age Aegean. (New York: Oxford University Press 2010), 310-311.
 Byrd, William. Bronze Javelin Head. Mercer University. Accessed March 24, 2015. http://libraries.mercer.edu/repository/handle/10898/386.
 Hartzler, Bruce. Warrior Vase. Mycenae. Accessed March 04, 2015. http://hartzler.org/cc307/mycenaean/index.html.
 ibid., 85-86.
 Demand, Nancy H. The Mediterranean Context of Early Greek History. (Chichester, U.K.: Wiley-Blackwell 2011), 193.
[19 &20] Drews, Robert. The End of the Bronze Age: Changes in Warfare and the Catastrophe Ca. 1200 B.C. Princeton, NJ: (Princeton University Press 1993), 86.
 Bryce, Trevor, and Adam Hook. Hittite Warrior. (Oxford: Osprey 2007), 6-9.