before conquering the world with legions, tradition has it that rome discovered that true power did not lie in gold, but in a humbler and yet indispensable resource: salt. whoever controlled salt controlled the preservation of food and, with it, the very survival of peoples.
towards the end of the seventh century bce, with the warlike tullus hostilius dead, the senate chose a king of the opposite cast: ancus marcius, grandson of numa, more calculating than martial. and, according to the account, he knew how to see rome’s structural problem. the city sat landlocked, several kilometres from the sea, dependent on its neighbours for everything that came by water. without its own outlet to the coast, it would never rise above being a local power.
salt was the only means of preserving meat and fish. to control it was to control hunger: that is why they called it the white gold of antiquity.
the chronicles relate that ancus marcius led his army down the course of the tiber to its mouth, on the tyrrhenian coast, and there founded the first roman colony: the port of ostia. rome ceased to be an isolated outpost and was linked to the maritime routes of the mediterranean. a historiographical caution is in order: archaeology does not detect a colony at ostia until the fourth century bce, long after the regal period, so the foundation by ancus marcius belongs to legend rather than to the material record. what tradition is really trying to explain is the origin of a double bond: that of rome with the sea, and that of rome with salt.
for the treasure lay on the very shore. at the mouth of the tiber stood the salt pans, and tradition attributes to rome the control of that production and the creation of the via salaria (the “salt road”), to distribute the white gold inland. one much-repeated myth is worth dismantling here: it is often said that the word “salary” comes from roman soldiers being paid in rations of salt. it is not so. salarium (a payment) is indeed etymologically related to sal (salt), but there is no evidence that the legions were paid in salt; the literal interpretation of payment in salt rations has no support in the ancient sources and stems from a late folk etymology.
with commerce came wealth, and with wealth, growth. tradition likewise credits ancus marcius with the first wooden bridge over the tiber — the pons sublicius (the bridge of piles) — and the digging of the dreaded prison of the forum, the carcer (the dungeon) at the foot of the capitol where rome would imprison her enemies for centuries. the resulting portrait is of a king who, without great wars, endowed the city with infrastructure, with revenue and with administrative form.
it is worth setting salt in its ancient context to understand why legend chooses it as the foundation of power. without refrigeration, salting was the only way to preserve meat and fish for months, to provision armies on campaign and to trade in foodstuffs over long distances: salt was not just another commodity, it was the underpinning of survival. for that reason the salt routes were strategic arteries throughout the mediterranean, and for that reason too the symbolic force of the account. and although the foundation of ostia by ancus marcius is legendary, it points to a deeper historical truth: rome’s destiny would be bound forever to that estuary. under the empire, ostia would become the great port of the capital, the gateway through which the grain of egypt entered and on which the sustenance of a million mouths depended. tradition, in attributing its origin to a king, did no more than acknowledge how ancient and vital that connection was.
the meaning of the episode lies in that change of character: rome ceases to be a camp of shepherds and warriors and turns into a commercial power with interests, routes and customs houses. but prosperity has its price. a wealthy city draws the gaze of the ambitious, and during the reign of ancus marcius there settled in rome an extraordinarily wealthy immigrant, come from advanced etruria, ready to buy the crown from within.
