For six centuries beginning around 500 BCE, ancient Peru was ravaged by nearly constant war. But the end result might almost have been worth it: that war seems to have been the driving force for the region's first complex civilization.
The Peru of the first millennium BCE was full of smaller groups, but it isn't until the region endured centuries of war that two large, dominant societies emerged in the vicinity of Lake Titicaca: the Taraco along the Ramis River and the Pukara of the grassland pampas. UCLA archaeologist Charles Stanish explains just what they were looking for as evidence of more advanced cultures:
"This study is part of a larger, worldwide comparative research effort to define the factors that gave rise to the first societies that developed public buildings, widespread religions and regional political systems — or basically characteristics associated with ancient states or what is colloquially known as 'civilization.' War, regional trade and specialized labor are the three factors that keep coming up as predecessors to civilization."
So, how do we know it's war and not regional trade or specialized labor that fueled the birth of civilization in Peru? Well, excavations in 2004 and 2006 turned up evidence of a massive fire in Taraco that had raged during the first century CE. The entire ancient state was largely reduced to ash and rubble. The size of the blaze and the fact that the archaeological record shows no evidence of attempted reconstruction suggests that this was part of a war, not an accident or some sort of ceremony - indeed, it might well record the last day of the war, but obviously there's no way to know that for sure.
Based on the archaeological record, the centuries of war correlate with great developments in agriculture, pottery, and the use of obsidian, all of which went into sharp decline after the fire. The archaeologists suggest that raids between the developing Taraco and Pukara had gone on for centuries, creating something of a feedback loop that helped shape the political landscape and perhaps even fueled the violent transference of knowledge between the two states. By the time Pukara fell around 200 CE, it was home to 10,000 people, not to mention huge monolithic sculptures adorned with complicated artwork. Again, that all fell away when the wars stopped and the city was abandoned.
While we're still working out the precise contours of just why something as seemingly destructive as war should be able to have a "civilizing" influence, there's similar evidence for this effect in ancient Central America and Mesopotamia. Stanish next hopes to examine a Neolithic site in Armenia for further evidence of this phenomenon.
Via PNAS. Image of modern settlement on Lake Titicaca via.