Dardanelles
The Dardanelles (Turkish: Çanakkale Boğazı), formerly Hellespont, is a narrow strait in northwestern Turkey connecting the Aegean Sea with the Sea of Marmara. It is 61 km (38 miles) long but only 1.2 to 6 km (0.75 to 4 miles) wide.
Just like the Bosporus strait, it separates Europe (in this case the Gallipoli peninsula) and the mainland of Asia. The major city adjoining the strait is Çanakkale (which takes its name from its famous castles; kale means "castle"). The name Dardanelles derives from Dardanus, an ancient Greek city on the Asian shore of the strait.
The strait has long had a strategic role in history. The ancient city of Troy was located near the western entrance of the strait and the strait's Asiatic shore was the focus of the Trojan War. The Persian army of Xerxes I and later the Macedonian army of Alexander the Great crossed the Dardanelles in opposite directions to invade each other's lands. The Dardanelles were vital to the defence of Constantinople during the Byzantine period, and since the 14th century they have almost continuously been controlled by the Turks.
Gaining control of or special access to the strait became a key foreign policy goal of the Russian Empire during the 19th century. This alarmed the Western powers, who feared the consequences of potential Russian expansionism in the Mediterranean. In 1841, Britain, France, Austria and Prussia forced Russia to agree that only Turkish warships could traverse the Dardanelles in peacetime. This convention was formally reaffirmed by the Congress of Paris in 1856, following the Russian defeat in the Crimean War, and it remained theoretically in force into the 20th century.
As a result of the strait being vital for the Ottoman's domination over their eastern Mediterranean dominion, the Allies made a failed attempt to seize the Dardanelles during World War I (the battle was officially declared lost on March 18, 1915); the high number of casualties (see ANZAC) from this battle almost ended the career of Winston Churchill.
Following the war, the 1920 Treaty of Sévres demilitarized the strait and made it an international territory. This was amended under the 1923 Treaty of Lausanne which restored the straits to Turkey. The Turks subsequently remilitarized the area, a status that was formalised under the Montreux Convention. The strait is today treated as an international shipping lane but Turkey retains the right to restrict the naval traffic of non-Black Sea nations.