Overview
Trastevere is the 13th of Rome: it is identified by the initials R. XIII and it is located within Municipio I. Its name comes from Latin , literally 'beyond the Tiber'.
Its coat of arms depicts a golden head of a lion on a red background, the meaning of which is uncertain.
History
In Rome's Regal period (753–509 BC), the area across the Tiber belonged to the Etruscans: the Romans named it Ripa Etrusca (Etruscan bank). Rome conquered it to gain control of and access to the river from both banks, but was not interested in building on that side of the river. In fact, the only connection between Trastevere and the rest of the city was a small wooden bridge called the Pons Sublicius (English: 'bridge on wooden piles').
From Wikipedia (CC BY-SA 4.0).