The Mediterranean Sea in Roman times was the internal sea of the Roman Empire. For this reason, the Romans used to call it mare nostrum, literally “our sea”. This term appears for the first time during the conquest of Sicily, Sardinia and Corsica during the First Punic War.
By 30 BCE the Roman state had sea waters from the Iberian Peninsula to Egypt under its control. At that point, the term applied to the entire Mediterranean Basin. Another term was also in use: Mare Internum (“Inner Sea”) when Mediterraneum Mare did not catch on until after the fall of Rome in 476 CE.