A coherent culture began to emerge in the Almeria region of southeastern Spain around 3,500 BC. The Chalcolithic, or Copper Age, had arrived, and rich deposits of the metal were available here. Climatology tells us the region was also wetter at the time, so it was a good place for the recently-invented technologies of animal husbandry and farming to flourish as well. Population boomed, and the copper flowed out across the Atlantic and Mediterranean worlds alongside their characteristic bell-shaped pottery.
This progress came with a new problem, however: wealth, or more importantly the inequalities of wealth created by any inherently unstable system of ownership. Whereas hunter-gatherer societies and the early proto-cities practiced communal ownership, consciously imposing absolute equality on everyone, these new societies were marked by pyramidal hierarchy associated with control of things of value. Because those people and their things needed protection from other people who wanted those things, Chalcolithic cities like Los Millares, seen above, were often built with a new civic invention: walls.
Not all city walls of this period are defensive by design. For instance, the perfectly-squared wall plans of Harrapan cities were clearly designed to regulate trade and limit smuggling, while the biblical walls of Jericho have been disputed as probable flood walls rather than defensive walls. Nevertheless, many of these constructions were unambiguously defensive, such as the walls of Los Millares. Someone was afraid of someone else and built a wall to keep them out. Fortification and location are force multipliers for the defender, and these purposes are plain to see in archaeology.
We might also think of these as gated communities. Multiple rings of wall were erected out onto the rock promontory between two rivers as the city enlarged to over half a mile in size, with the original ring apparently retaining its status as the top of the city hierarchy.
Outlying forts guard all the approaches, providing defense in depth. The main wall is protected by a 400 meter (about a quarter-mile) long moat, hewn right out of the rock with copper tools. This project speaks to powerful civic mobilization — and military minds at work. Note the towers, which allow enfilading fire. That is, the distance between towers is as far as the flight of an arrow from a simple bow, so that two archers, one on top of each tower, can defend with crossfire any section of wall from a much larger number of people trying to storm it by climbing up ladders. Two gatehouses complete the system: any attacker at one gate must guard their flank against the other one, from which the occupants can sally in a counterstrike.
To overwhelm these defenses in a lightning raid, one would need an army of at least hundreds, with advanced planning and training for the operation. To encircle and besiege this city would require thousands of men eating a small mountain of food over at least a few weeks — material, logistical demands that would seriously challenge far more developed states than this one. While the city lies near enough to the coast to be an entry port for the region, an enemy would still need a whole navy to take advantage of the port for a prolonged siege.
There was nothing “primitive” about this advanced tactical thinking, however rude the materials were. Indeed, Los Millares is an excellent example of what I mean by the word “primitive.” These people were not stupid or uneducated or incapable at all. On the contrary, we ought to marvel at just how brilliant such “primitives” really were, and are today wherever such societies survive. (Could you survive a single day in their world?)
These walls seem to have been unchallenged, as the city never burned. After 1,000 years of occupation, Los Millares was probably abandoned around 2,250 BC. The reasons are unclear, but the city clearly was not destroyed by violence. Rather, we must look to climate change, shifting trade patterns, or something as simple as the desire to build something new. Put simply, these walls worked. As Picasso said when he first saw cave art up close: “In 15,000 years we have invented nothing!” This is almost even true of poliorcetics. The art of fortification warfare, particularly city walls, is as old as the city itself, an arms race older than written history. The walls came first, then the writing.