The sea was over 2500 miles from North to South and about 800 miles from East to West at its widest most point from continent to continent. The straits connecting the Inner Seas to the East Sea in the north and the Belegaer (Great Sea) in the south were no more than 100 miles from continent to continent. It is not known whether these seas were calm or rough but all that can be conjectured is that they probably had both warm and cold currents, due to its proximity to the heats of the south and the darkness of the north.
Years of the Trees and First AgeEdit
The origins of the Inner Seas can be traced back to the changes in the overall symmetry of the world as a result of the destructive tumults caused by Melkor and the Valar's confrontations with him for the sake of the Children of Ilúvatar. Its present position and location between Middle-earth and Dark Land seem to date from the end of the Battle of the Powers at the conclusion of the War for Sake of the Elves. From that time on, the Inner Seas were joined with the East Sea and known by the same name.
Second Age and beyondEdit
At the conclusion of the War of Wrath it became known as the Inner Seas. The island of Númenor was raised and its inhabitants became great mariners but with the Ban of the Valar, they could not sail into the furthermost west where the Undying Lands lay. This restricted them to what lies east. They sailed the Inner Seas exploring the whole of its latitudes. After the Change of the World and the Fall of Númenor, the Inner Seas may have remained intact though whether they were still known as the Inner Seas is not known.