Bosphorus in the context of "Gallipoli campaign"

The Aegean Sea is an elongated embayment of the Mediterranean Sea between Europe and Asia. It is located between the Balkans and Anatolia, and covers an area of some 215,000 km (83,000 sq mi). In the north, the Aegean is connected to the Marmara Sea, which in turn connects to the Black Sea, by the straits of the Dardanelles and the Bosphorus, respectively. The Aegean Islands are located within the sea and some bound it on its southern periphery, including Crete and Rhodes. The sea reaches a maximum depth of 2,639 m (8,658 ft) to the west of Karpathos. The Thracian Sea and the Sea of Crete are main subdivisions of the Aegean Sea.

The Aegean Islands can be divided into several island groups, including the Dodecanese, the Cyclades, the Sporades, the Saronic islands and the North Aegean Islands, as well as Crete and its surrounding islands. The Dodecanese, located to the southeast, includes the islands of Rhodes, Kos, and Patmos; the islands of Delos and Naxos are within the Cyclades to the south of the sea. Lesbos is part of the North Aegean Islands. Euboea, the second-largest island in Greece, is located in the Aegean, despite being administered as part of Central Greece. Nine out of twelve of the Administrative regions of Greece border the sea, along with the Turkish provinces of Edirne, Çanakkale, Balıkesir, İzmir, Aydın and Muğla to the east of the sea. Various Turkish islands in the sea are Imbros, Tenedos, Cunda Island, and the Foça Islands.

Istanbul is the largest city in Turkey, constituting the country's economic, cultural, and historical heart. With a population over 15 million, it is home to 18% of the population of Turkey. Istanbul is among the largest cities in Europe and in the world by population. It is a city on two continents; about two-thirds of its population live in Europe and the rest in Asia. Istanbul straddles the Bosphorus—one of the world's busiest waterways—in northwestern Turkey, between the Sea of Marmara and the Black Sea. Its area of 5,461 square kilometers (2,109 sq mi) is coterminous with Istanbul Province. Under the Köppen climate classification, Istanbul's climate is considered a form of Mediterranean climate, with aspects of other temperate climate types.

The city now known as Istanbul developed to become one of the most significant cities in history. Byzantium was founded on the Sarayburnu promontory by Greek colonists, potentially in the seventh century BC. Over nearly 16 centuries following its reestablishment as Constantinople in 330 AD, it served as the capital of four empires: the Roman Empire (330–395), the Byzantine Empire (395–1204 and 1261–1453), the Latin Empire (1204–1261), and the Ottoman Empire (1453–1922). It was instrumental in the advancement of Christianity during Roman and Byzantine times, before the Ottomans conquered the city in 1453 and transformed it into an Islamic stronghold and the seat of the last caliphate. Although the Republic of Turkey established its capital in Ankara, palaces and imperial mosques still line Istanbul's hills as visible reminders of the city's previous central role. The historic centre of Istanbul is a UNESCO World Heritage Site.

Heraclius (Greek: Ἡράκλειος, romanized: Hērákleios; c. 575 – 11 February 641) was Byzantine emperor from 610 to 641. His rise to power began in 608, when he and his father, Heraclius the Elder, the Exarch of Africa, led a revolt against the unpopular emperor Phocas.

Heraclius's reign was marked by several military campaigns. The year Heraclius came to power, the empire was threatened on multiple frontiers. Heraclius immediately took charge of the Byzantine–Sasanian War of 602–628. The first battles of the campaign ended in defeat for the Byzantines; the Persian army fought their way to the Bosphorus but Constantinople was protected by impenetrable walls and a strong navy, and Heraclius was able to avoid total defeat. Soon after, he initiated reforms to rebuild and strengthen the military. Heraclius drove the Persians out of Asia Minor and pushed deep into their territory, defeating them decisively in 627 at the Battle of Nineveh. The Persian Shah Khosrow II was overthrown and executed by his son Kavad II, who soon sued for a peace treaty, agreeing to withdraw from all occupied territory. This way peaceful relations were restored to the two deeply strained empires.

The Gallipoli campaign, the Dardanelles campaign, the Defence of Gallipoli or the Battle of Gallipoli (Turkish: Gelibolu Muharebesi, Çanakkale Muharebeleri or Çanakkale Savaşı) was a military campaign in the First World War on the Gallipoli Peninsula (now Gelibolu) from 19 February 1915 to 9 January 1916. The Entente powers, Britain, France and the Russian Empire, sought to weaken the Ottoman Empire, one of the Central Powers, by taking control of the Turkish straits. This would expose the Ottoman capital at Constantinople to bombardment by Entente battleships and cut it off from the Asian part of the empire. With the Ottoman Empire defeated, the Suez Canal would be safe and the Bosphorus and Dardanelles straits would be open to Entente supplies to the Black Sea and warm-water ports in Russia.

In February 1915 the Entente fleet failed to force a passage through the Dardanelles. An amphibious landing on the Gallipoli peninsula began in April 1915. In January 1916, after eight months' fighting, with approximately 250,000 casualties on each side, the land campaign was abandoned and the invasion force was withdrawn. It was a costly campaign for the Entente powers and the Ottoman Empire as well as for the sponsors of the expedition, especially the First Lord of the Admiralty (1911–1915), Winston Churchill. The campaign was considered a great Ottoman victory. In Turkey, it is regarded as a defining moment in the history of the state, a final surge in the defence of the motherland as the Ottoman Empire retreated.

There are 50 passenger ferry quays in Istanbul, the largest city in Turkey with a population of 16,237,000 in 2025. 37 of the ferry quays are in active service in Bosphorus, Golden Horn and the Sea of Marmara. As of the 2017 Summer season, the ferry quays are served at 600 voyages daily by 28 traditional passenger ferry boats on 17 lines operated by the Şehir Hatları ("City Lines") company.

Karaköy (Turkish pronunciation: [kaˈɾakøj]), the modern name for the old Galata, is a commercial quarter in the Beyoğlu district of Istanbul, Turkey, located at the northern part of the Golden Horn mouth on the European side of Bosphorus.

Karaköy is one of the oldest and most historic districts of the city, and is today an important commercial center and transport hub. It is connected with the surrounding neighborhoods by streets radiating out from Karaköy Square. The Galata Bridge links Karaköy to Eminönü to the southwest, Tersane Street links it to Azapkapı to the west, Voyvoda Street (Bankalar Caddesi) links it to Şişhane to the northwest, the steeply sloping Yüksek Kaldırım Street links it to Pera in the north, and Kemeraltı Street and Necatibey Street link it to Tophane to the northeast.