But obviously their story is not the whole story of this ancient region, let alone that of the ancient world. Soon after 2000 BC the movements of other peoples were already breaking it up into new patterns. A thousand years later, other centres of civilization were in existence elsewhere and we are well into the historical era. Unfortunately for the historian, there is no simple and obvious unity to this story even in the Fertile Crescent, which for a long time continued to show more creativity and dynamism than any other part of the world. There is only a muddle of changes whose beginnings lie far back in the second millennium and which go on until the first of a new succession of empires emerges in the ninth century BC.
The sweeping upheavals and rearrangements which stud this confusion are hard even to map in outline, let alone to explain; fortunately, their details do not need to be unravelled here. History was speeding up and civilization was providing men with new opportunities. Rather than submerge ourselves in the flood of events, we can more usefully try to grasp some of the change-making forces at work. The most obvious of these forces for change continue to be great migrations. Their fundamental pattern does not change much for a thousand years or so after 2000 BC , nor does the ethnic cast of the drama. The basic dynamic was provided by the pressure of peoples of Indo-European linguistic stocks on the Fertile Crescent from both east and west.
Their variety and numbers grow but their names need not be remembered here even if some of them bring us to the remote origins of Greece. Meanwhile, Semitic peoples dispute with the Indo-Europeans the Mesopotamian valleys; with Egypt and the mysterious ‘Peoples of the Sea’ they fi ght over Sinai, Palestine and the Levant. Another group of northerners establishes itself in Iran – and from it will eventually come the greatest of all the empires of the ancient past, that of sixth-century Persia. Still another branch of these peoples pushes out into India. These movements must explain much of what lies behind a shifting pattern of empires and kingdoms stretching across the centuries. By the standards of modern times some of them were quite long-lived; from about 1600 BCa people called Kassites from Caucasia ruled in Babylon for four and a half centuries, which is a duration comparable to that of the entire history of the British overseas empire. Yet, by the standards of Egypt such polities are the creatures of a moment, born today and swept away tomorrow.
It would indeed be surprising if they had not proved fragile in the end, for many other new forces were also at work which multiplied the revolutionary effects of the wanderings of peoples. One of them which has left deep traces is improvement in military technique. Fortifi cation and, presumably, siege-craft had already reached a fairly high level in Mesopotamia by 2000 BC . Among the Indo-European peoples who nibbled at the civilization these skills protected were some with recent nomadic origins; perhaps for that reason they were able to revolutionize warfare in the fi eld, though they long remained unskilled in siege-craft. Their introduction of the two-wheeled war chariot and the cavalryman transformed operations in open country. In the river valleys horses were at first rare, the prized possessions of kings or great leaders, and the barbarians therefore enjoyed a great military and psychological superiority. Eventually, though, chariots were used in the armies of all the great kingdoms of the Middle East; they were too valuable a weapon to be ignored. When the Egyptians expelled the Hyksos, they did so by, among other things, using this weapon against those who had conquered them with it.
Warfare was changed by riding horses, too. A cavalryman proper not only moves about in the saddle but fi ghts from horseback; it took a long time for this art to be developed, for managing a horse and a bow or a spear at the same time is a complex matter. Horse-riding came from the Iranian highlands, where it may have been practised as early as 2000 BC. It spread through the Middle East and Aegean well before the end of the next millennium. Later, after 1000 BC , there appeared the armoured horseman, charging home and dominating foot-soldiers by sheer weight and impetus. This was the beginning of a long era in which heavy cavalry were a key weapon, though their full value could only be exploited centuries later when the invention of the stirrup gave the rider real control of his horse.