Throughout most of history a multipolar world is pretty much the norm. Even during short periods of bipolar eras, they usually fell back to multipolarity rather quickly. Likewise the unipolar world is rather unique.
Let's go back to ancient times. Egypt was a great power from the dawn of civilization. Blessed with the Nile, Egypt had abundance of grain. However, given its ease at maintaining its wealth, it rarely was a military power.
Its nearest neighbors were various small kingdoms and city-states to the northeast, who stood as a buffer between Egypt and Anatolia (modern Turkey) and Mesopotamia (modern Iraq). Egypt was relatively safe and secure, as long as Anatolia and Mesopotamia were divided.
The Hittites had an empire in eastern Anatolia. Here is a map from approximately 1300 BC.
Mesopotamia was divided, but an organized empire to the north was dangerous. Pharoah Ramses II was born around 1303 BC, the son and grandson of conquerors. His predecessors had fought off sea raiders and invaded Canaan.
This put Egypt in direct conflict with the Hittites. The Hittites had subjected the former rulers of northern Mesopotamia, the Mittani. It set up a bipolar world with two empires in conflict.
The young Ramses II brought his army north and in 1274 BC the largest chariot battle up to that time occurred at the Battle of Kadesh. This well documented battle has been preserved in stone engravings and approximately 6,000 chariots fought. The Egyptians had a lighter 2 person chariot versus the heavier 3 person Hittite version.
The battle was more or less a draw and Ramses returned to Egypt and declared a victory. He ended up with a long reign, living to the age of 90 and dying around 1213 BC. A peace treaty fixing boundaries was signed in 1258 BC.
This draw marked the furthest expansion of Egyptian direct expansion, but it was also the beginning of the end of the Hittite empire. The upstart Assyrians largely destroyed the Hittite empire before Ramses died. Invaders from the west furthered the damage.
What can we learn from this? Watch out for new threats. The Hittites could stop Egyptian expansion, but new threats in all other directions existed. No one should expect a geopolitical system to last too long.
Egypt had its natural advantages. Fighting a long ways from home made for difficult logistics. Better to just keep distance from the big drama elsewhere.
Throughout history there have been times when two powers exhaust themselves only to lose out to a new rising power.