Mare Nostrum
The term mare nostrum was used in the first place by Romans to refer to the Tyrrhenian Sea. This was after they had taken over the countries around it. These were Sicily, Sardinia and Corsica. It happened during the Punic Wars with Carthage. When they controlled Hispania they expanded the term to the whole western Mediterranean. By 30 BC, the Romans had taken over the countries around the Mediterranean from the Iberian Peninsula to Egypt. So they started to use the name mare nostrum for the whole Mediterranean Sea. They used other names as well, such as Mare Internum ("The Internal Sea"). However, they did not use the name "Mediterranean" (Middle Sea), as this name came later.