The Dardanelles, also called the Strait of Gallipoli, is a narrow, natural waterway in northwestern Turkey. It divides Asia and Europe and separates Asian Turkey from European Turkey. Along with the Bosporus, the Dardanelles forms the Turkish Straits.

This strait is one of the narrowest waterways in the world used for international travel. It connects the Sea of Marmara to the Aegean and Mediterranean Seas. It also allows ships to travel to the Black Sea through the Bosporus. The Dardanelles is 61 kilometers (38 miles) long and 1.2 to 6 kilometers (0.75 to 3.73 miles) wide. Its average depth is 55 meters (180 feet), and its deepest point, near the city of Çanakkale, is 103 meters (338 feet). A bridge across the Dardanelles opened in 2022, called the 1915 Çanakkale Bridge.

The northern side of the strait along the Gallipoli Peninsula (in Turkish, Gelibolu) has few people living there. The southern side, along the Troad Peninsula (in Turkish, Biga), is home to Çanakkale’s city population of 110,000 people.

Names

The modern Turkish name Çanakkale Boğazı, which means "Çanakkale Strait," comes from the city of Çanakkale located near the strait. The city's name means "pottery fort," combining the words "çanak" (meaning "pottery") and "kale" (meaning "fortress"). This reflects the area's well-known pottery and ceramic products, as well as the historic Ottoman fortress called Sultaniye.

The English name "Dardanelles" is a shortened form of "Strait of the Dardanelles." During the Ottoman Empire, there were castles on both sides of the strait. Together, these castles were called the Dardanelles. The name likely comes from Dardanus, an ancient city on the Asian side of the strait. Dardanus is said to be named after a mythical figure, Dardanus, who was the son of Zeus and Electra. According to some sources, the name also relates to the Dardani, a group of people from the Balkans.

The ancient Greek name for the strait was Ἑλλήσποντος (Hellēspontos), meaning "Sea of Helle." This was the original name for the narrow waterway. In ancient writings, the strait was also called Hellespontium Pelagus, Rectum Hellesponticum, and Fretum Hellesponticum. These names all reference Helle, the daughter of King Athamas. In Greek mythology, Helle drowned in the strait after falling from a golden flying ram during the story of the Golden Fleece.

Geography

The Dardanelles is a waterway that connects different seas in the Eastern Mediterranean, the Balkans, the Near East, and Western Eurasia. It specifically links the Aegean Sea to the Sea of Marmara. The Sea of Marmara connects to the Black Sea through the Bosporus, while the Aegean Sea connects to the Mediterranean Sea. This allows ships to travel from the Black Sea to the Mediterranean Sea, and further to the Atlantic Ocean through the Strait of Gibraltar or to the Indian Ocean via the Suez Canal. Because of this, the Dardanelles is a vital international waterway, especially for the movement of goods between Russia, Ukraine, and other countries near the Black Sea.

The Dardanelles’ geography has made it important for military and strategic reasons. The strait is long, narrow, and has many curves and sharp turns. Its shores include high cliffs and bluffs that extend into the water. The length of the strait and the shape of the land on both sides allow control of ship passage from land-based positions that are not affected by water. Control of this area has been a point of conflict in many historical events, such as the ancient Greco-Persian and Peloponnesian Wars, the Gallipoli Campaign during World War I, and the Turkish War of Independence.

The Dardanelles is 61 kilometers (38 miles) long and ranges in width from 1.2 to 6 kilometers (0.7 to 3.7 miles). It averages a depth of 55 meters (180 feet), with a maximum depth of 103 meters (338 feet) at its narrowest point near Nara Burnu, near Çanakkale. Two major currents flow through the strait: a surface current moves from the Black Sea toward the Aegean Sea, and a saltier undercurrent flows in the opposite direction.

The Dardanelles is unique as a natural formation. Its narrow, winding shape resembles a river. It is the only connection between two much larger bodies of water, causing strong tidal movements and currents. For ships, this makes the Dardanelles one of the most dangerous and challenging waterways in the world. Tidal currents from the Black Sea and the Sea of Marmara are so strong that ships using sails must wait at anchor until conditions are safe before entering the Dardanelles.

History

The Dardanelles is the only passage between the Black Sea and the Mediterranean. It has always been important for trade and military reasons and remains important today. Many countries, including Russia and Ukraine, use the Dardanelles as a major sea route. Control over the strait has been a goal in many conflicts, such as the Allied attack during the 1915 Battle of Gallipoli in World War I.

The ancient city of Troy was near the western entrance of the strait. The Trojan War took place on the Asiatic side of the strait. Troy controlled the ships that passed through this important waterway. In 480 BC, the Persian army of Xerxes I crossed the Dardanelles to invade Greece. Later, in 334 BC, the Macedonian army of Alexander the Great crossed the strait in the opposite direction to invade Persia.

According to Herodotus, around 482 BC, Xerxes I built two pontoon bridges across the Hellespont at Abydos to help his army cross from Persia into Greece. Aeschylus called this event the cause of divine intervention against Xerxes. Both bridges were destroyed by a storm, and Xerxes ordered the builders to be executed. He also punished the strait by throwing fetters into the water, lashing it with whips, and branding it with hot irons. Herodotus noted that this was a harsh way to treat the Hellespont but typical of Xerxes. Harpalus, an engineer, helped armies cross by tying ships together and adding anchors to each ship.

In ancient Greek mythology, Helle, the daughter of Athamas, drowned at the Dardanelles in the story of the Golden Fleece. The strait was also the setting for the legend of Hero and Leander, where Leander swam across the strait every night to meet Hero, but he drowned in a storm.

During the Byzantine period, the Dardanelles was vital for defending Constantinople. It was a major source of income for the region’s ruler. A 6th-century AD marble plate at the Istanbul Archaeological Museum contains a law by Emperor Anastasius I that set rules for paying fees when ships passed through the Dardanelles. The law stated that anyone who broke these rules would be punished and that officials could collect 50 golden Litrons to ensure the rules were followed. Specific fees were set for merchants of wine, olive oil, vegetables, lard, and wheat.

The Dardanelles remained an important waterway during the Ottoman Empire, which conquered Gallipoli in 1354. Ottoman control of the strait lasted with few interruptions until the 19th century, when the empire began to decline.

During the 19th century, the Russian Empire aimed to gain control or guaranteed access to the strait. In 1807, during the Napoleonic Wars, Russia—supported by Britain—blockaded the strait. In 1833, after the Ottoman Empire lost the Russo-Turkish War, Russia forced the Ottomans to sign the Treaty of Hunkiar Iskelesi, which allowed Russia to close the strait to warships from non-Black Sea powers. This alarmed the Ottomans, who feared Russian expansion in the Black Sea and Mediterranean regions.

In 1841, the London Straits Convention, supported by the UK, France, Austria, and Prussia, limited the use of the Dardanelles to Turkish warships in peacetime. During the Crimean War (1853–1856), the UK and France used the strait to attack the Crimean Peninsula as allies of the Ottoman Empire. The 1856 Congress of Paris reaffirmed the London Straits Convention.

In 1915, Allied forces, including British, Indian, Australian, New Zealand, French, and Newfoundland troops, tried to capture the Gallipoli peninsula to open the strait. Turkish troops trapped the Allies, damaging the career of Winston Churchill, who had promoted the failed naval attack. Mustafa Kemal Atatürk, later founder of the Republic of Turkey, led Ottoman forces during the campaign.

Turks placed mines in the strait to stop Allied ships, but British and Australian submarines managed to pass through. The British submarine sank an old Turkish battleship near Istanbul. The Allied campaign failed, and the British withdrew in December 1915 after eight months of fighting. Total Allied deaths included 41,000 British and Irish, 15,000 French, 8,700 Australians, 2,700 New Zealanders, 1,370 Indians, and 49 Newfoundlanders. Turkish deaths were around 60,000.

After World War I, the 1920 Treaty of Sèvres made the strait an international territory under the League of Nations. The Ottoman Empire’s non-Turkish territories were divided among Allied Powers, and Turkey’s control over the strait was limited.

Following the Turkish War of Independence, the Republic of Turkey was created in 1923 by the Treaty of Lausanne, which restored the strait to Turkish control but required it to remain demilitarized and open to all ships.

Turkey later rejected these terms and remilitarized the strait. The Montreux Convention of 1936, still in effect today, allows Turkey to control the strait while keeping it open to all ships. The convention treats the strait as an international shipping lane but lets Turkey restrict non-Black Sea naval traffic.

During World War II, the Dardanelles remained a key strategic location.

Crossings

The Dardanelles Strait is crossed daily by many ferries that carry passengers and vehicles, as well as recreational and fishing boats of various sizes, including small dinghies and large yachts owned by public and private groups. The strait also sees heavy traffic from commercial ships.

The 1915 Çanakkale Bridge connects Lapseki, a district of Çanakkale on the Asian side, to Sütlüce, a village in the Gelibolu district on the European side. It is part of planned improvements to the Turkish National Highway Network. The bridge opened in March 2022.

Two underwater power lines carry electricity at 400 kV across the Dardanelles to supply areas west and east of Istanbul. These lines have landing stations in Lapseki and Sütlüce. The first line, located in the northeast part of the strait, was activated in April 2015 and provides 2 gigawatts of power through six phases of 400 kV AC over a 3.9 km (2.4 mi) underwater route. Both power lines cross four earlier laid optical fiber data lines along the strait. A published map shows communication lines extending from Istanbul into the Mediterranean, named MedNautilus, with landing points in Athens, Sicily, and other locations.