“Begin at the beginning,” the King said gravely, “and go on until you come to the end: then stop.” -Alice’s Adventures in Wonderland

Following the good King’s advice, I thought it suitable to begin this blog with a few thoughts about the beginnings of the city. As he knew so well every story has its beginning, and traditionally the story of Rome begins with a tale of sibling rivalry between the legendary founder of the city, Romulus, and his unfortunate brother Remus in 753 BC.

However, as with any narrative, and although it may have caused the King of Hearts some consternation, one can look further and further back, ad infinitum, to find the events which led to this ‘beginning’. In the case of Rome, we can usefully go back a further half a million years to find the serendipitous events which created the fortunate geographical and geological situation found just below the centre of the western coast of the Italian peninsula. These elements were to have a defining role in the creation of a settlement which exercised almost a thousand years of domination over the Mediterranean, and which remains one of the most recognized cities on earth.

South of Rome lie the Alban Hills. Dotted with lakes, the area’s height means its cooler climes have long been conducive to those seeking respite from the summer heat of the city and, perhaps most famously, it has been the place of the summer residence of the Popes at Castelgandolfo since the 17th century. The papal retreat is on the eastern shores of Lake Albano, the crater of the youngest volcano in the area which last erupted in the late Bronze Age (roughly a millennium before Christ). This group of volcanoes, known as the volcanic system of Latium was, however, most active much earlier, and the vast majority of the material they deposited is the product of their first known phase of activity, between 600,000 and 300,000 years ago.

To the north of the city are the remains of another group of volcanoes. The lakes of Bracciano, Trevignano and Anguillara are the traces left by the Sabatine volcanic system. Both of these clusters of volcanoes were of the explosive type; their eruptions ‘exploded’ the mountain, showering the surrounding area with its debris. The materials which travelled furthest were the fragments and dust from the top of the volcano which settled, creating the friable tufa rock so characteristic of the area. This sedimentary formation was slowly eroded by waters which made their way to the Tyrrhenian coast from the mountains of the Apennines, which make up the spine of the Italian peninsula. This watercourse was the nascent river Tiber.

Rome’s position is entirely dependent on the presence of the Tiber. In the earliest periods of settlement it would provide a route for the trafficking of salt from the marshes along the coast at Ostia to the peoples of the Apennines. The city grew up in what was once a fordable point, the area which would become the Forum Boarium and which, as we will see, would become so important in the city’s earliest legends. This crossing of the Tiber was to provide a link between the Latins south of the river, and the Etruscans to the north. It was along the Tiber that Rome would to begin her domination of the Mediterranean, umpteen millennia after those fierce eruptions.

The greatest achievements of the Roman world were to remain, throughout her history, inextricably linked to this accident of geography. That the Imperial city would grow to a population of over a million inhabitants, the largest the world had ever seen, was made possible by an ingeniously developed, and ample, supply of fresh water. That most Roman of inventions, the aqueduct, was the inspired exploitation of the abundant natural springs within these extinct volcanoes around the city. Similarly, the first of the great Roman roads, the Appian Way, began tracing its path across country along a lava flow which provided a solid base for the legions which were to march along it for the best part of the next millennium.

This geological genius loci makes itself felt in every aspect of the Roman world; without the loose dusty volcanic sand (pozzolana), and the lime from the travertine which abounds near Tivoli, east of Rome, concrete would not have been developed, bringing with it the rich architectural possibilities of vaults and domes and masonry bridges. The travertine itself is the stone from which triumphal arches and amphitheatres was constructed. The multiple levels of the sixty complexes of catacombs beneath the outlying areas of the ancient city exist because of the ease with which the ubiquitous tufa could be excavated.

The great symbols of the ancient city – the Colosseum, the Pantheon and the Baths of Caracalla; indeed the very seven hills on which it grew, their spurs carved by the industrious Tiber – are the product of these ancient volcanoes. This geological advantage, and the inventiveness with which it was exploited, lies behind every temple and every church, every bridge and every obelisk.