Tiber River

The Tiber River, stretching 405 kilometers from the Apennine Mountains to the Tyrrhenian Sea, has been central to Rome’s development since its founding in 753 BCE. From its earliest days, the river shaped Rome’s infrastructure, culture, and religion, helping the city grow from a small settlement into a monarchy, a republic, and eventually an empire.

In Roman religion, the Tiber was personified as the god Tiberinus, honored as both protector and life-giver. The river also plays a key role in Rome’s founding myth. According to legend, the twins Romulus and Remus, sons of Mars and the vestal virgin Rhea Silvia, were abandoned along the Tiber’s banks. A she-wolf discovered the twins and nursed them until a shepherd took them in. Romulus later founded Rome near the river and the seven hills on April 21, 753 BCE. While this founding date was widely accepted by the Romans, the written version of the myth appeared much later, during the late third century BCE.

Throughout its history, the Tiber River has been both a vital resource and a major challenge. It supplied fresh water, supported trade, and connected Rome to its port at Ostia. However, frequent and destructive floods forced the Romans to develop sophisticated water management systems. Floods were recorded as early as 414 BCE and repeatedly damaged the city, posing serious health risks. To address this, the Romans constructed the Cloaca Maxima. Originally an open canal, its purpose was to drain the swampland between the Palatine and Capitoline hills, bring fresh water from the Tiber River into the Roman Forum, and help mitigate the natural flood cycles. Over time, the Cloaca Maxima was expanded into a fully enclosed sewer system, collecting wastewater and draining it into the Tiber.

Flooding continued to plague Rome long after antiquity. In 1598, the Tiber rose nearly 20 meters above its normal level, submerging large parts of the city, including the densely populated Jewish quarter. A stone marker on the façade of Santa Maria sopra Minerva still records the height of this flood. Another devastating flood occurred in 1870, just months after Rome became the capital of a newly unified Italy. Water levels reached 17.22 meters above normal, flooding areas like the Campus Martius, Piazza del Popolo, and Via del Corso, bringing sewage, mud, and disease into the city.

To solve the ongoing flood problem, Italy’s parliament debated several proposals. Revolutionary leader Giuseppe Garibaldi suggested building a canal to divert the river around the city. Others proposed demolishing Tiber Island. However, the plan that was adopted came from engineer Raffaele Canevari. He proposed building massive travertine embankment walls, known as muraglioni, standing 17 to 18 meters high and spaced 100 meters apart along the river’s banks. Construction of these floodwalls began in 1876 and continued until 1910. Their construction required demolishing many historic buildings, particularly in Rome’s Jewish quarter, as well as destroying parts of the Aurelian Walls. Tiber Island itself was heavily modified during this project.

Today, the muraglioni still stand, controlling the Tiber’s floods and protecting Rome from the river that once nourished and threatened the city.

Bibliography

• Allen, Bruce. (2019). Tiber: Eternal River of Rome. University Press of New England. https://www.jstor.org/stable/j.ctv1xx99s8
• Heiken, Grant, Renato Funiciello, and Donatella De Rita. (2005). “The Tiber Floodplain, Commerce, and Tragedy.” In The Seven Hills of Rome: A Geological Tour of the Eternal City, 59–84. Princeton University Press. https://www.jstor.org/stable/j.ctt4cgbkz.9
• McGregor, James. (2006). “Tiber Island and the Ancient Port.” In Rome from the Ground Up, 5–32. Harvard University Press. https://www.jstor.org/stable/j.ctv1c7zfqb.4
• Scoccolo, Travis. “Engineering the Tiber: A History of Symbolism, Degradation, and Resurrection.” Engineering Rome. https://engineeringrome.org/engineering-the-tiber-a-history-of-symbolism-degradation-and-resurrection/