The longest river on the Italian peninsula, the Tiber River flows 250 miles through central Italy. Near the end of its journey, it flows through Rome before emptying into the Mediterranean Sea. In ancient Roman times, the river formed the border between the regions of Etruria and Latium.
The Tiber begins as a creek in the Apennines of Etruria, not far from the present-day city of Arezzo. As it flows south and then southwest, it is joined by several other rivers and streams before reaching Rome. The writer Pliny the Elder gave the number of tributaries as 42, but that figure proved to be an underestimate.
At the city of Rome, the Tiber divides in two as it flows around Tiber Island. In Roman times, this spot provided the first crossing point on the river between Rome and the river’s mouth at the port of Ostia on the coast.
Navigation on the Tiber River was possible along more than half of its length, but sailors found it dangerous because of the swift current. Flooding along its banks was a constant problem. The emperor Augustus appointed a river commission to manage the river’s banks and channels.
The Romans often called the Tiber flavus Tiberis (yellow Tiber) because of its muddy yellowish color. This color results from large quantities of silt*, which the Tiber deposits at its mouth. In ancient times, the accumulation of silt created problems for the harbor at Ostia by constantly advancing the shoreline there. The emperor Claudius tried to solve this problem by having Roman workers dig through the silt and create an artificial harbor.
* silt fine particles of earth and sand carried by moving water
During the imperial* age, wealthy Romans built large country estates along the banks of the lower part of the Tiber. (See also Ships and Shipbuilding; Trade, Roman; Transportation and Travel.)
* imperial pertaining to an emperor or empire