Question

The nation that eventually became the Roman Republic began on the Tiber River in what modern-day country

Answer 1

Italy

The Tiber River (in Italian Tevere) is the third longest river in Italy (after the Po and Adige rivers), with a length of 405 km.

It was born in the Apennines, on Mount Fumaiolo, in the Romagna region, and crosses those of Umbria and Lazio, passing through the cities of Perugia and Rome. It empties into the Tyrrhenian Sea, which reaches divided into two arms in Ostia, the Isola Sacra (to the south) and Fiumicino (to the north).

From its birth, Rome was linked to the river. In fact he owes his own existence to him as it is already described from the first scene of the founding legend with Romulus and Remus in the basket deposited on the banks of the Tiber.

Answer 2

The modern day country is called Italy.