The Tiber (/ˈtaɪbər/ TY-bər; Italian: Tevere [ˈteːvere];[1] Latin: Tiberis[2]) is the third-longest river in Italy and the longest in Central Italy, rising in the Apennine Mountains in Emilia-Romagna and flowing 406 km (252 mi) through Tuscany, Umbria, and Lazio, where it is joined by the River Aniene, to the Tyrrhenian Sea, between Ostia and Fiumicino.

The river has achieved lasting fame as the main watercourse of the city of Rome, which was founded on its eastern banks.

The river rises at Mount Fumaiolo in Central Italy and flows in a generally southerly direction past Perugia and Rome to meet the sea at Ostia.

[4][5] However, it does not form a proportional delta, owing to a strong north-flowing sea current close to the shore, due to the steep shelving of the coast, and to slow tectonic subsidence.

[8][9] Legendary king Tiberinus, ninth in the king-list of Alba Longa, was said to have drowned in the River Albula, which was afterwards called Tiberis.

[10] Tiberis/Tifernus may be a pre-Indo-European substrate word related to Aegean tifos "still water", Greek phytonym τύφη a kind of swamp and river bank weed (Typha angustifolia), Iberian hydronyms Tibilis, Tebro and Numidian Aquae Tibilitanae.

Legend says Rome's founders, the twin brothers Romulus and Remus, were abandoned on its waters, where they were rescued by the she-wolf, Lupa.

The Romans connected the river with a sewer system (the Cloaca Maxima) and with an underground network of tunnels and other channels, to bring its water into the middle of the city.

The heavy sedimentation of the river made maintaining Ostia difficult, prompting the emperors Claudius and Trajan to establish a new port on the Fiumicino in the first century AD.

They built a new road, the Via Portuensis, to connect Rome with Fiumicino, leaving the city by Porta Portese (the port gate).