The Silva Ciminia, the Ciminian Forest, was the unbroken primeval forest that separated Ancient Rome

Ancient Rome

Ancient Rome was a thriving civilization that grew on the Italian Peninsula as early as the 8th century BC. Located along the Mediterranean Sea and centered on the city of Rome, it expanded to one of the largest empires in the ancient world....

 from Etruria

Etruria

Etruria—usually referred to in Greek and Latin source texts as Tyrrhenia—was a region of Central Italy, an area that covered part of what now are Tuscany, Latium, Emilia-Romagna, and Umbria. A particularly noteworthy work dealing with Etruscan locations is D. H...

. According to the Roman historian Livy

Livy

Titus Livius — known as Livy in English — was a Roman historian who wrote a monumental history of Rome and the Roman people. Ab Urbe Condita Libri, "Chapters from the Foundation of the City," covering the period from the earliest legends of Rome well before the traditional foundation in 753 BC...

 it was, in the 4th century BCE, a feared, pathless wilderness in which few dared tread. The Ciminian Forest received its name from the Monti Cimini, which are still a densely wooded range of volcanic hills northwest of Rome

Rome

Rome is the capital of Italy and the country's largest and most populated city and comune, with over 2.7 million residents in . The city is located in the central-western portion of the Italian Peninsula, on the Tiber River within the Lazio region of Italy.Rome's history spans two and a half...

. They form the part of the forerange of the Apennine

Apennine mountains

The Apennines or Apennine Mountains or Greek oros but just as often used alone as a noun. The ancient Greeks and Romans typically but not always used "mountain" in the singular to mean one or a range; thus, "the Apennine mountain" refers to the entire chain and is translated "the Apennine...

 main range that faces towards the Tyrrhenian Sea

Tyrrhenian Sea

The Tyrrhenian Sea is part of the Mediterranean Sea off the western coast of Italy.-Geography:The sea is bounded by Corsica and Sardinia , Tuscany, Lazio, Campania, Basilicata and Calabria and Sicily ....

.

In the south, the Silva Ciminia stretched from Lake Bracciano

Lake Bracciano

Lake Bracciano is a lake of volcanic origin in the Italian region of Lazio, northwest of Rome. It is the second largest lake in the region and one of the major lakes of Italy...

 to the edges of the flat plain of the Roman Campagna, in the lower Tiber valley. Stretches of cleared fields round the major Etruscan settlements formed the Ager Veientanus that supported Veii

Veii

Veii was, in ancient times, an important Etrurian city NNW of Rome, Italy; its site lies in Isola Farnese, a village of Municipio XX, an administrative subdivision of the comune of Rome in the Province of Rome...

, the Ager Faliscus of the Falisci

Falisci

Falisci is the ancient Roman exonym for an Italic people who lived in what was then Etruria, on the Etruscan side of the Tiber River. The region is now entirely Lazio. They spoke an Italic language, Faliscan, closely akin to Latin. Originally a sovereign state, politically and socially they...

, and the Ager Capenas of Capena

Capena

Capena is a town and comune in the province of Rome, Lazio region . The town has borrowed its modern name from a pre-Roman and Roman settlement that was located three kilometres to its north....

. In the heart of the Ciminian woodlands lay the Lake of Ciminus (Lago di Vico). In the northwest, they reached as far as Tarquinia

Tarquinia

Tarquinia, formerly Corneto and in Antiquity Tarquinii, is an ancient city in the province of Viterbo, Lazio, Italy.- History :Tarquinii is said to have been already a flourishing city when Demaratus of Corinth brought in Greek workmen...

.

The forest was predominantly formed by oak

Oak

An oak is a tree or shrub in the genus Quercus , of which about 600 species exist. "Oak" may also appear in the names of species in related genera, notably Lithocarpus...

 and beech

Beech

Beech is a genus of ten species of deciduous trees in the family Fagaceae, native to temperate Europe, Asia and North America.-Habit:...

, though second growth in the lower slopes has favoured the aggressively re-seeding Spanish chestnut. A relict stand

Relict

A relict is a surviving remnant of a natural phenomenon.* In biology a relict is an organism that at an earlier time was abundant in a large area but now occurs at only one or a few small areas....

 of beech, rare in Central Italy

Central Italy

Central Italy is one of the five official statistical regions of Italy used by the National Institute of Statistics , a first level NUTS region and a European Parliament constituency...

, remains on the upper slopes of Monte Cimino. Sub-fossil pollen analyses

Palynology

Palynology is the science that studies contemporary and fossil palynomorphs, including pollen, spores, orbicules, dinoflagellate cysts, acritarchs, chitinozoans and scolecodonts, together with particulate organic matter and kerogen found in sedimentary rocks and sediments...

 from cores of stratified sediment taken in the region's crater lake

Crater lake

A crater lake is a lake that forms in a volcanic crater or caldera, such as a maar; less commonly and with lower association to the term a lake may form in an impact crater caused by a meteorite. Sometimes lakes which form inside calderas are called caldera lakes, but often this distinction is not...

s typically reveal a pollen sequence characteristic of tundra

Tundra

In physical geography, tundra is a biome where the tree growth is hindered by low temperatures and short growing seasons. The term tundra comes through Russian тундра from the Kildin Sami word tūndâr "uplands," "treeless mountain tract." There are three types of tundra: Arctic tundra, alpine...

 lying over an all-but-sterile wind-blown loess

Loess

Loess is an aeolian sediment formed by the accumulation of wind-blown silt, typically in the 20–50 micrometre size range, twenty percent or less clay and the balance equal parts sand and silt that are loosely cemented by calcium carbonate...

 sand; this in turn was followed by grassland, with pollen of water-lilies and pondweeds blown from glacial meltwater lake

Glacial lake

A glacial lake is a lake with origins in a melted glacier. Near the end of the last glacial period, roughly 10,000 years ago, glaciers began to retreat. A retreating glacier often left behind large deposits of ice in hollows between drumlins or hills. As the ice age ended, these melted to create...

s. The earliest Holocene forest was fir

Fir

Firs are a genus of 48–55 species of evergreen conifers in the family Pinaceae. They are found through much of North and Central America, Europe, Asia, and North Africa, occurring in mountains over most of the range...

, followed by mixed pine and oak, with a climax forest of beech and oak, including Quercus ilex.

The surface profiles have been transformed since the region was first deforested in Roman times, as settlers worked outwards from strips flanking the Roman road

Roman road

The Roman roads were a vital part of the development of the Roman state, from about 500 BC through the expansion during the Roman Republic and the Roman Empire. Roman roads enabled the Romans to move armies and trade goods and to communicate. The Roman road system spanned more than 400,000 km...

s — the via Cassia

Via Cassia

The Via Cassia was an important Roman road striking out of the Via Flaminia near the Milvian Bridge in the immediate vicinity of Rome and, passing not far from Veii traversed Etruria...

, the via Amerina and the via Flaminia

Via Flaminia

The Via Flaminia was an ancient Roman road leading from Rome over the Apennine Mountains to Ariminum on the coast of the Adriatic Sea, and due to the ruggedness of the mountains was the major option the Romans had for travel between Etruria, Latium and Campania and the Po Valley...

 — which had been struck through the forest. In the deforested slopes, streams with even moderate flow have cut deeply eroded gullies and valleys in the geologically very recent soft tuff

Tuff

Tuff is a type of rock consisting of consolidated volcanic ash ejected from vents during a volcanic eruption. Tuff is sometimes called tufa, particularly when used as construction material, although tufa also refers to a quite different rock. Rock that contains greater than 50% tuff is considered...

 and volcanic ash. A sudden increase in organic sediments in strata corresponding to the third century BCE records this erosion

Erosion

Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...

 following agrarian deforestation, which, far downstream, would initiate the Tiber

Tiber

The Tiber is the third-longest river in Italy, rising in the Apennine Mountains in Emilia-Romagna and flowing through Umbria and Lazio to the Tyrrhenian Sea. It drains a basin estimated at...

's delta. Thereafter the palynological record attests many cultivated plants, and, significantly, nettle

Nettle

Nettles constitute between 24 and 39 species of flowering plants of the genus Urtica in the family Urticaceae, with a cosmopolitan though mainly temperate distribution. They are mostly herbaceous perennial plants, but some are annual and a few are shrubby...

s, the weed of disturbed, untended corners that follows temperate agriculture everywhere. By the third and fourth centuries CE very little of the primeval forest survived.

To the Romans of the Republic, the forest was as much feared as the trackless Hercynian Forest

Hercynian Forest

The Hercynian Forest was an ancient and dense forest that stretched eastward from the Rhine River across southern Germany and formed the northern boundary of that part of Europe known to writers of antiquity. The ancient sources are equivocal about how far east it extended...

 would be when they encountered that. In 310 BCE the Roman Senate

Roman Senate

The Senate of the Roman Republic was a political institution in the ancient Roman Republic, however, it was not an elected body, but one whose members were appointed by the consuls, and later by the censors. After a magistrate served his term in office, it usually was followed with automatic...

, even after the rout of the Etruscans at Sutrium, charged the consul Fabius Maximus Rullianus

Fabius Maximus Rullianus

Quintus Fabius Maximus Rullianus , son of Marcus Fabius Ambustus, of the patrician Fabii of ancient Rome, was five times consul and a hero of the Samnite Wars. He was brother to Marcus Fabius Ambustus ....

not to enter this woodland in pursuit of the Etruscans, and when it emerged that he had done so, all Rome was struck with terror. The Silva formed a natural barrier between Roman and Etruria.