The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Southern Europe and Anatolia, on the south by North Africa and on the east by the Levant. Although the sea is sometimes considered a part of the Atlantic Ocean, it is usually identified as a separate body of water. Geological evidence indicates that around 5.9 million years ago, the Mediterranean was cut off from the Atlantic and was partly or completely desiccated over a period of some 600,000 years, the Messinian salinity crisis, before being refilled by the Zanclean flood about 5.3 million years ago.
It covers an approximate area of 2.5 million km2 (965,000 sq mi), but its connection to the Atlantic (the Strait of Gibraltar) is only 14 km (8.7 mi) wide. The Strait of Gibraltar is a narrow strait that connects the Atlantic Ocean to the Mediterranean Sea and separates Gibraltar and Spain in Europe from Morocco in Africa. In oceanography, it is sometimes called the Eurafrican Mediterranean Sea or the European Mediterranean Sea to distinguish it from mediterranean seas elsewhere.
The Mediterranean Sea has an average depth of 1,500 m (4,900 ft) and the deepest recorded point is 5,267 m (17,280 ft) in the Calypso Deep in the Ionian Sea. The sea is bordered on the north by Europe, the east by Asia, and in the south by Africa. It is located between latitudes 30° and 46° N and longitudes 6° W and 36° E. Its west-east length, from the Strait of Gibraltar to the Gulf of Iskenderun, on the southwestern coast of Turkey, is approximately 4,000 km (2,500 miles). The sea's average north-south length, from Croatia’s southern shore to Libya, is approximately 800 km (500 miles). The Mediterranean Sea, including the Sea of Marmara (connected by the Dardanelles to the Aegean Sea), has a surface area of approximately 2,510,000 square km (970,000 square miles).
The sea was an important route for merchants and travellers of ancient times that allowed for trade and cultural exchange between emergent peoples of the region. The history of the Mediterranean region is crucial to understanding the origins and development of many modern societies.
With its highly indented coastline and large number of islands, Greece has the longest Mediterranean coastline.
The Ancient Greeks called the Mediterranean simply η θάλασσα 'the Sea' or sometimes η μεγάλη θάλασσα 'the Great Sea', η ημέτερα θάλασσα 'Our Sea', or η θάλασσα η καθ'εμάς 'the sea around us'. The Romans called it Mare Magnum 'Great Sea' or Mare Internum 'Internal Sea' and, starting with the Roman Empire, Mare Nostrum 'Our Sea'. The term Mare Mediterrāneum appears later: Solinus apparently used it in the 3rd century, but the earliest extant witness to it is in the 6th century, in Isidore of Seville. It means 'in the middle of land, inland' in Latin, a compound of medius 'middle', terra 'land, earth' and -āneus 'having the nature of'. The Latin word is a calque of Greek μεσόγαιος 'inland', from μέσος 'in the middle' and γήϊος 'of the earth' (from γῆ 'land, earth'). The original meaning may have been 'the sea in the middle of the earth', rather than 'the sea enclosed by land'.
The Carthaginians called it the "Syrian Sea". In ancient Syrian texts, Phoenician epics and in the Hebrew Bible, it was primarily known as the "Great Sea" (הַיָּם הַגָּדוֹל, HaYam HaGadol, Numbers 34:6,7; Joshua 1:4, 9:1, 15:47; Ezekiel 47:10,15,20) or simply as "The Sea" (1 Kings 5:9; compare1 Macc. 14:34, 15:11); however, it has also been called the "Hinder Sea" (הַיָּם הָאַחֲרוֹן) because of its location on the west coast of Greater Syria or the Holy Land (and therefore behind a person facing the east), which is sometimes translated as "Western Sea", (Deut. 11:24; Joel 2:20). Another name was the "Sea of the Philistines" (יָם פְּלִשְׁתִּים, Exod. 23:31), from the people inhabiting a large portion of its shores near the Israelites. In Modern Hebrew, it is called HaYam HaTikhon (הַיָּם הַתִּיכוֹן) 'the Middle Sea'.
In Modern Arabic, it is known as al-Baḥr [al-Abyaḍ] al-Mutawassiṭ (البحر [الأبيض] المتوسط) 'the [White] Middle Sea'. In Islamic and older Arabic literature, it was Baḥr al-Rūm(ī) (بحر الروم or بحر الرومي}) 'the Sea of the Romans' or 'the Roman Sea'. At first, that name referred to only the Eastern Mediterranean, but it was later extended to the whole Mediterranean. Other Arabic names were Baḥr al-šām(ī) (يبحر الشرومام) 'the Sea of Syria' and Baḥr al-Maghrib (بحرالمغرب) 'the Sea of the West'.
In Turkish, it is the Akdeniz 'the White Sea'; in Ottoman, ﺁق دكيز, which sometimes means only the Aegean Sea. The origin of the name is not clear, as it is not known in earlier Greek, Byzantine or Islamic sources. It may be to contrast with the Black Sea. In Persian, the name was translated as Baḥr-i Safīd, which was also used in later Ottoman Turkish. It is probably the origin of the colloquial Greek Άσπρη Θάλασσα.
Johann Knobloch claims that in Classical Antiquity, cultures in the Levant used colours to refer to the cardinal points: black referred to the north (explaining the name Black Sea), yellow or blue to east, red to south (i.e., the Red Sea), and white to west. This would explain both the Turkish Akdeniz (White Sea) and the Arab nomenclature described above.