The Dardanelles (Turkish: Çanakkale Boğazı, Greek: Δαρδανελλια), formerly known as the Hellespont, is a narrow strait in northwestern Turkey connecting the Aegean Sea with the Sea of Marmara. One of the Turkish Straits with Istanbul Strait. It is located at approximately 40°13′N 26°26′E. The strait is 61 km (38 miles) long but only 1.2 to 6 km (0.75 to 4 miles) wide, averaging 55 m (180 ft) deep with a maximum depth of 82 m (300 ft). Water flows in both directions along the strait, from the Sea of Marmara to the Aegean via a surface current and in the opposite direction via an undercurrent.

Just like the Bosporus strait, it separates Europe (in this case the Gallipoli peninsula) and the mainland of Asia. The strait is an International waterway and together with the Bosporus connect the Black Sea to the Mediterranean Sea.

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.

History

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. It was also the scene of the legendary Greek story of Hero and Leander. 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, in 480 BC and 334 BC respectively. 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 or special access to the strait became a key foreign policy goal of the Russian Empire during the 19th century. During the Napoleonic Wars, Russia — supported by Great Britain in the Dardanelles Operation — blockaded the straits in 1807. Following the Ottoman Empire's defeat in the Russo-Turkish War of 1828-1829, in 1833 Russia forced the Turks to sign the Treaty of Hunkiar Iskelesi which required the straits to be closed to warships of non-Black Sea powers at Russia's request. This would have effectively given Russia a free hand in the Black Sea.

The treaty alarmed the Western powers, who feared the consequences of potential Russian expansionism in the Mediterranean. At the London Straits Convention in July 1841, the United Kingdom, France, Austria and Prussia forced Russia to agree that only Turkish warships could traverse the Dardanelles in peacetime. The United Kingdom and France subsequently sent their fleets through the straits to attack Crimea during the Crimean War in 1853, though this was done as allies of the Ottoman Empire. 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.

The Allies made a failed attempt to seize the Dardanelles during World War I, seeking to knock the Ottoman Empire out of the conflict. The Battle of Gallipoli damaged the career of Winston Churchill, the First Lord of the Admiralty who eagerly promoted the use of Royal Navy battleships to force open the straits. The straits were mined to prevent Allied ships from penetrating them, although a British submarine did succeed in evading the minefields and sank a Turkish battleship off the Golden Horn in Istanbul. Sir Ian Hamilton's Mediterranean Expeditionary Force was unsuccessful in its attempt to capture the Gallipoli peninsula, and a withdrawal was ordered in January 1916.

Following the war, the 1920 Treaty of Sèvres demilitarized the strait and made it an international territory under the control of the League of Nations. This was amended under the 1923 Treaty of Lausanne which restored the straits to Turkey but allowed all foreign warships to traverse the straits freely. Turkey rejected the terms of this treaty and subsequently remilitarized the area. The reversion to this old regime was formalised under the Montreux Convention of July 1936. The convention, which is still in force today, treats the straits as an international shipping lane but Turkey retains the right to restrict the naval traffic of non-Black Sea nations (like Greece or Algeria). During World War II, when Turkey was neutral for almost the entire length of the conflict, the Dardanelles were closed to the ships of the belligerent nations.

Dardanus