The ancient Romans relied on long-distance timber trading to construct their empire, according to a new study.

The timber requirements of ancient Rome were immense and complex, with different types of trees from various locations around the Roman Empire and beyond used for many purposes, including construction, shipbuilding and firewood. Unfortunately, the timber trade in ancient Rome is poorly understood, as little wood has been found in a state adequate for analysis. In this study, Bernabei et al successfully date and determine the origin and chronology of unusually well-preserved ancient Roman timber samples.

The twenty-four oak timber planks (Quercus species) analyzed in this study were excavated during Metro construction in Rome during 2014-2016. They formed part of a Roman portico in the gardens of via Sannio (belonging to what was once a lavishly decorated and rich property). The authors measured the tree-ring widths for each plank and ran statistical tests to determine average chronology, successfully dating thirteen of the planks.

By comparing their dated planks to Mediterranean and central European oak reference chronologies, the authors found that the oaks used for the Roman portico planks were taken from the Jura mountains in eastern France, over 1700km away.

Fig 5. The timber road
Fig 5. The timber road © Map sourced from - Map of Roman provinces in today’s France and Germany, with the probable provenance of the Roman oak Metro samples. Some important Roman towns are indicated (Colonia Agrippina = Cologne; Augusta Treverorum = Trier; Divodurum = Metz; Dorocortorum = Reims; Augustobona = Troyes; Lugdunum = Lyon; Arelate = Arles; Aquae Sextiae = Aix-en-Provence and Massilia = Marseilles), as well as the regions where the reference chronologies (Table 3) come from and also the rivers (Saône and Rhône) leading to the Mediterranean Sea.

Mauro Bernabei, Jarno Bontadi, Rossella Rea, Ulf Büntgen, Willy Tegel. Dendrochronological evidence for long-distance timber trading in the Roman EmpirePLOS ONE, 2019; 14 (12): e0224077

DOI: 10.1371/journal.pone.0224077

An important question for our understanding of Roman history is how the Empire’s economy was structured, and how long-distance trading within and between its provinces was organised and achieved. Moreover, it is still unclear whether large construction timbers, for use in Italy, came from the widespread temperate forests north of the Alps and were then transported to the sparsely-wooded Mediterranean region in the south. Here, we present dendrochronological results from the archaeological excavation of an expensively decorated portico in the centre of Rome. The oak trees (Quercus sp.), providing twenty-four well-preserved planks in waterlogged ground, had been felled between 40 and 60 CE in the Jura Mountains of north-eastern France. It is most likely that the wood was transported to the Eternal City on the Saône and Rhône rivers and then across the Mediterranean Sea. This rare dendrochronological evidence from the capital of the Roman Empire gives fresh impetus to the ongoing debate on the likelihood of transporting timber over long distances within and between Roman provinces. This study reconstructs the administrative and logistic efforts required to transport high-quality construction timber from central Europe to Rome. It also highlights an advanced network of trade, and emphasises the enormous value of oak wood in Roman times.