Dardanelles

The strait is 61 kilometres (38 mi) long, and 1.2 to 6 kilometres (0.7 to 3.7 mi) wide, averaging 55 metres (180 ft) deep with a maximum depth of 103 metres (338 ft) at its narrowest point at Nara Burnu, abreast Çanakkale.[3] There are two major currents through the strait: a surface current flows from the Black Sea towards the Aegean Sea, and a more saline undercurrent flows in the opposite direction.[4]

The Dardanelles is unique in many respects. The very narrow and winding shape of the strait is more akin to that of a river. It is considered one of the most hazardous, crowded, difficult and potentially dangerous waterways in the world. The currents produced by the tidal action in the Black Sea and the Sea of Marmara are such that ships under sail must await at anchorage for the right conditions before entering the Dardanelles.

An artist's illustration depicting Xerxes' alleged "punishment" of the Hellespont.

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. Troy was able to control the marine traffic entering this vital waterway. The Persian army of Xerxes I of Persia 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.

Herodotus says that, circa 482 BC, Xerxes I (the son of Darius) had two pontoon bridges built across the width of the Hellespont at Abydos, in order that his huge army could cross from Persia into Greece. This crossing was named by Aeschylus in his tragedy The Persians as the cause of divine intervention against Xerxes.[5]

According to Herodotus (vv.34), both bridges were destroyed by a storm and Xerxes had those responsible for building the bridges beheaded and the strait itself whipped. The Histories of Herodotus vii.33–37 and vii.54–58 give details of building and crossing of Xerxes' Pontoon Bridges. Xerxes is then said to have thrown fetters into the strait, given it three hundred lashes and branded it with red-hot irons as the soldiers shouted at the water.[6]

Herodotus commented that this was a "highly presumptuous way to address the Hellespont" but in no way atypical of Xerxes. (vii.35)

Harpalus the engineer eventually helped the invading armies to cross by lashing the ships together with their bows facing the current and, so it is said, two additional anchors.

From the perspective of ancient Greek mythology, it was said that Helle, the daughter of Athamas, was drowned at the Dardanelles in the legend of the Golden Fleece. Likewise, the strait was the scene of the legend of Hero and Leander, wherein the lovesick Leander swam the strait nightly in order to tryst with his beloved, the priestess Hero, and was drowned in a storm.

The Dardanelles were vital to the defence of Constantinople during the Byzantine period.

Also, the Dardanelles was an important source of income for the ruler of the region. At the Istanbul Archaeological Museum a marble plate contains a law by the Byzantine Emperor Anastasius I (491–518 AD), that regulated fees for passage through the customs office of the Dardanelles. Translation:

... Whoever dares to violate these regulations shall no longer be regarded as a friend, and he shall be punished. Besides, the administrator of the Dardanelles must have the right to receive 50 golden Litrons, so that these rules, which we make out of piety, shall never ever be violated... ... The distinguished governor and major of the capital, who already has both hands full of things to do, has turned to our lofty piety in order to reorganize the entry and exit of all ships through the Dardanelles... ... Starting from our day and also in the future, anybody who wants to pass through the Dardanelles must pay the following:

– All wine merchants who bring wine to the capital (Constantinopolis), except Cilicians, have to pay the Dardanelles officials 6 follis and 2 sextarius of wine.
– In the same manner, all merchants of olive-oil, vegetables and lard must pay the Dardanelles officials 6 follis. Cilician sea-merchants have to pay 3 follis and in addition to that, 1 keration (12 follis) to enter, and 2 keration to exit.

– All wheat merchants have to pay the officials 3 follis per modius, and a further sum of 3 follis when leaving.

Since the 14th century the Dardanelles have almost continuously been controlled by the Turks.

The Dardanelles continued to constitute an important waterway during the period of the Ottoman Empire, which conquered Gallipoli in 1354.

Ottoman control of the strait continued largely without interruption or challenges until the 19th century, when the Empire started its decline.

Gaining control of or guaranteed 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 pressured the Ottomans to sign the Treaty of Hunkiar Iskelesi—which required the closing of the straits to warships of non-Black Sea powers at Russia's request. That would have effectively given Russia a free hand in the Black Sea.

That treaty alarmed the losers, who were concerned that the consequences of potential Russian expansionism in the Black Sea and Mediterranean regions could conflict with their own possessions and economic interest in the region. At the London Straits Convention in July 1841, the United Kingdom, France, Austria, and Prussia pressured 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 defend the Danube front and to attack the Crimean Peninsula during the Crimean War of 1853–1856 – but they did so as allies of the Ottoman Empire. Following the defeat of Russia in the Crimean War, the Congress of Paris in 1856 formally reaffirmed the London Straits Convention. It remained technically in force into the 20th and 21st centuries.

1915 Landing of French troops in Moudros (Lemnos island) during the Gallipoli Campaign

Landing at Gallipoli in April 1915

Anzac Cove

The Sphinx overlooking Anzac Cove

In 1915 the Allies sent a substantial invasion force of British, Indian, Australian, New Zealand, French and Newfoundland troops to attempt to open up the straits. In the Gallipoli campaign, Turkish troops trapped the Allies on the coasts of the Gallipoli peninsula. The campaign did damage to the career of Winston Churchill, then the First Lord of the Admiralty (in office 1911–1915), who had eagerly promoted the unsuccessful use of Royal Navy sea-power to force open the straits. Mustafa Kemal Atatürk, later founder of the Republic of Turkey, served as a commander for the Ottomans during the land campaign.

The Turks mined the straits to prevent Allied ships from penetrating them, but in minor actions, two submarines, one British and one Australian, did succeed in penetrating the minefields. The British submarine sank an obsolete Turkish pre-dreadnought battleship off the Golden Horn of Istanbul. Sir Ian Hamilton's Mediterranean Expeditionary Force failed in its attempt to capture the Gallipoli peninsula, and the British cabinet ordered its withdrawal in December 1915, after eight months' fighting. Total Allied deaths included 43,000 British, 15,000 French, 8,700 Australians, 2,700 New Zealanders, 1,370 Indians and 49 Newfoundlanders.[7] Total Turkish deaths were around 60,000.

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. The Ottoman Empire's non-ethnically Turkish territories were broken up and partitioned among the Allied Powers, and Turkish jurisdiction over the straits curbed.

After the dissolution of the Ottoman Empire following a lengthy campaign by Turks as part of the Turkish War of Independence against both the Allied Powers and the Ottoman court, the Republic of Turkey was created in 1923 by the Treaty of Lausanne, which established most of the modern sovereign territory of Turkey and restored the straits to Turkish territory, with the condition that Turkey keep them demilitarized and allow all foreign warships and commercial shipping to traverse the straits freely.

As part of its national security strategy, Turkey eventually rejected the terms of the treaty, and subsequently remilitarized the straits area over the following decade. Following extensive diplomatic negotiations, the reversion was formalized under the Montreux Convention Regarding the Regime of the Turkish Straits on 20 July 1936. That convention, which is still in force today, treats the straits as an international shipping lane while allowing Turkey to retain the right to restrict the naval traffic of non-Black Sea states.

During World War II, through February 1945, when Turkey was neutral for most of the length of the conflict, the Dardanelles were closed to the ships of the belligerent nations. Turkey declared war on Germany in February 1945, but it did not employ any offensive forces during the war.

In July 1946, the Soviet Union sent a note to Turkey proposing a new régime for the Dardanelles that would have excluded all nations except the Black Sea powers. The second proposal was that the straits should be put under joint Turkish-Soviet defence. This meant that Turkey, the Soviet Union, Bulgaria and Romania would be the only states having access to the Black Sea through the Dardanelles. The Turkish government however, under pressure from the United States, rejected these proposals.[8]

Turkey joined NATO in 1952, thus affording its straits even more strategic importance as a commercial and military waterway.

In more recent years, the Turkish Straits have become particularly important for the oil industry. Russian oil, from ports such as Novorossyisk, is exported by tankers primarily to western Europe and the U.S. via the Bosphorus and the Dardanelles straits.

The waters of the Dardanelles are traversed by numerous passenger and vehicular ferries daily, as well as recreational and fishing boats ranging from dinghies to yachts owned by both public and private entities.

The strait also experiences significant amounts of international commercial shipping traffic by freighters and tankers.

At present, there are no vehicular crossings across the strait. However, as part of planned expansions to the Turkish National Highway Network, the Turkish Government is considering the construction of a suspension bridge between Sarıçay (a district of Çanakkale Province) on the Asian side, to Kilitbahir on the European side, at the narrowest part of the strait.[9] In March 2017, construction of the Çanakkale 1915 Bridge between the cities of Gelibolu and Lapseki started.

2 submarine cable systems transmitting electric power at 400 kV voltage bridge the Dardanelles to feed west and east of Istanbul. They have their own landing stations in Lapseki and Sütlüce. The first, situated in the northeast quarter portion of the strait, has been energised in April 2015 and leads 2 GW via 6 phases 400 kV AC 3.9 km far thru the sea. The second, somewhat in the middle of the strait, has been still under construction in June 2016 and has quite similar data.

Both subsea power lines cross 4 optical fibre data lines laid earlier along the strait.[10] A published map shows communication lines leading from Istanbul into the Mediterranean, named MedNautilus and landing at Athens, Sicily and elsewhere.[11]