Siege of Constantinople (860)

Constantinople (; Greek: Κωνσταντινούπολις Kōnstantinoupolis; Latin: Constantinopolis; Ottoman Turkish: قسطنطينيه‎, romanized: Ḳosṭanṭīnīye) was the capital of the Roman/Byzantine Empire (330–1204 and 1261–1453), the Latin Empire (1204–1261), and the Ottoman Empire (1453–1922). The capital then moved to Ankara following the Turkish War of Independence. Officially renamed Istanbul in 1930, the city is today the largest city and financial centre of the Republic of Turkey (1923–present). It remains the largest city in Europe. In 324, the ancient city of Byzantium was renamed "New Rome" and declared the new capital of the Roman Empire by Emperor Constantine the Great, after whom it was renamed, and dedicated on 11 May 330. Constantinople is generally considered to be the center and the "cradle of Orthodox Christian civilization". From the mid-5th century to the early 13th century, Constantinople was the largest and wealthiest city in Europe. The city became famous for its architectural masterpieces, such as Hagia Sophia, the cathedral of the Eastern Orthodox Church, which served as the seat of the Ecumenical Patriarchate, the sacred Imperial Palace where the Emperors lived, the Galata Tower, the Hippodrome, the Golden Gate of the Land Walls, and opulent aristocratic palaces. The University of Constantinople was founded in the fifth century and contained artistic and literary treasures before it was sacked in 1204 and 1453, including its vast Imperial Library which contained the remnants of the Library of Alexandria and had 100,000 volumes. The city was the home of the Ecumenical Patriarch of Constantinople and guardian of Christendom's holiest relics such as the Crown of thorns and the True Cross. Constantinople was famed for its massive and complex fortifications, which ranked among the most sophisticated defensive architecture of Antiquity. The Theodosian Walls consisted of a double wall lying about 2 kilometres (1.2 mi) to the west of the first wall and a moat with palisades in front. Constantinople's location between the Golden Horn and the Sea of Marmara reduced the land area that needed defensive walls. The city was built intentionally to rival Rome, and it was claimed that several elevations within its walls matched Rome's 'seven hills'. The impenetrable defenses enclosed magnificent palaces, domes, and towers, the result of prosperity Constantinople achieved as the gateway between two continents (Europe and Asia) and two seas (the Mediterranean and the Black Sea). Although besieged on numerous occasions by various armies, the defenses of Constantinople proved impenetrable for nearly nine hundred years. In 1204, however, the armies of the Fourth Crusade took and devastated the city and, for several decades, its inhabitants resided under Latin occupation in a dwindling and depopulated city. In 1261 the Byzantine Emperor Michael VIII Palaiologos liberated the city, and after the restoration under the Palaiologos dynasty, it enjoyed a partial recovery. With the advent of the Ottoman Empire in 1299, the Byzantine Empire began to lose territories and the city began to lose population. By the early 15th century, the Byzantine Empire was reduced to just Constantinople and its environs, along with Morea in Greece, making it an enclave inside the Ottoman Empire; after a 53-day siege the city eventually fell to the Ottomans, led by Sultan Mehmed II, on 29 May 1453, whereafter it replaced Edirne (Adrianople) as the new capital of the Ottoman Empire.

The Battle of Constantinople was a naval battle between the fleets of the Empire of Nicaea and the Republic of Venice that occurred in May–June 1241 near Constantinople.

New Rome (Greek: Νέα Ῥώμη, Néa Rhṓmē; Koine Greek: [ˈne̞a ˈr̥o̞ːme̞ː]; Latin: Nova Roma; Late Latin: [ˈnɔwa ˈroma]) was the original name given by the Roman emperor Constantine the Great in 330 CE to his new imperial capital, which was built as an expansion of the city of Byzantium on the European coast of the Bosporus strait. The city was founded as Byzantion (Greek: Βυζάντιον) by Megarian colonists in 657 BCE. It was renamed by Constantine the Great first as "New Rome" (Nova Roma) during the official dedication of the city as the new Roman capital in 330 CE, which he soon afterwards changed to Constantinople (Constantinopolis). The city was officially renamed as Istanbul in the 20th century, after the establishment of the Turkish Republic in 1923. Constantine essentially rebuilt the city on a monumental scale from 326 to 330, partly modeling it after Rome. Names of this period included ἡ Νέα, δευτέρα Ῥώμη, "the New, second Rome"; Ἄλμα Ῥώμα, "Alma Roma"; Βυζαντιάς Ῥώμη, "Byzantine Rome"; ἑῴα Ῥώμη, "Eastern Rome"; and Roma Constantinopolitana.: 354 The term "New Rome" was used to indicate that Byzantium, thereafter Constantinople, was the second/new capital of the Roman Empire. In modern times, "New Rome" remains part of the official title of the Orthodox Ecumenical Patriarch of that city.During the Tetrarchy system established by Diocletian in the 3rd century, Nicomedia (modern İzmit) near Istanbul was the Eastern (and most senior) capital of the Roman Empire (Diocletian had his seat in Nicomedia as the Augustus of the East). The last Roman co-emperor in Nicomedia, Licinius, was defeated by Constantine at the Battle of Chrysopolis (in the modern Üsküdar district on the Asian side of Istanbul) on 18 September 324. Constantine used Nicomedia as his interim capital city between 324 and 330, while rebuilding and expanding Byzantium as Nova Roma (which he soon renamed again as Constantinopolis). Constantine died at a villa near Nicomedia on 22 May 337.

Istanbul ( IST-an-BUUL, US also IST-an-buul; Turkish: İstanbul [isˈtanbuɫ] (listen)), formerly known as Constantinople, is the largest city in Turkey, serving as the country's economic, cultural and historic hub. The city straddles the Bosporus strait, lying in both Europe and Asia, and has a population of over 15 million residents, comprising 19% of the population of Turkey. Istanbul is the most populous European city, and the world's 15th-largest city. The city was founded as Byzantium (Byzantion) in the 7th century BCE by Greek settlers from Megara. In 330 CE, the Roman emperor Constantine the Great made it his imperial capital, renaming it first as New Rome (Nova Roma) and then as Constantinople (Constantinopolis) after himself. The city grew in size and influence, eventually becoming a beacon of the Silk Road and one of the most important cities in history. The city served as an imperial capital for almost 1600 years: during the Roman/Byzantine (330–1204), Latin (1204–1261), late Byzantine (1261–1453), and Ottoman (1453–1922) empires. The city played a key role in the advancement of Christianity during Roman/Byzantine times, hosting four (including Chalcedon (Kadıköy) on the Asian side) of the first seven ecumenical councils (all of which were in present-day Turkey) before its transformation to an Islamic stronghold following the Fall of Constantinople in 1453 CE—especially after becoming the seat of the Ottoman Caliphate in 1517.In 1923, after the Turkish War of Independence, Ankara replaced the city as the capital of the newly formed Republic of Turkey. In 1930, the city's name was officially changed to Istanbul, the Turkish rendering of the appellation Greek speakers used since the eleventh century to colloquially refer to the city.Over 13.4 million foreign visitors came to Istanbul in 2018, eight years after it was named a European Capital of Culture, making it the world's eighth most visited city. Istanbul is home to several UNESCO World Heritage Sites, and hosts the headquarters of numerous Turkish companies, accounting for more than thirty percent of the country's economy.

The Mosque with the Spiral Minaret (Turkish: Burmalı Mescit Camii or Burmalı Minare Camii) is a 16th-century Ottoman mosque in Şarachane park, Fatih district, Istanbul, Turkey. Built in 1550 on behalf of Emin Nuretti Efendi, qadi 'asker of Egypt, it is named for its spiraling (burmalı) brick minaret, a copy of a Seljuq design that is unique in Istanbul. The mosque is not domed, but has a pitched porch, which rests on four reused Byzantine Corinthian stone columns. Unusually, the entrance is off-center behind a column. The mosque's interior is undistinguished.

On 7 June 2016, at around 08:40 (UTC+3), a bombing occurred in central Istanbul, Turkey, killing 12 people and injuring 51 others, three of them seriously. The attack targeted a bus carrying policemen as the vehicle passed through the Vezneciler district near the Şehzade Mosque and the Vezneciler Metro station.

The Philadelphion was a public square located in Constantinople.

The Şehzade Mosque (Turkish: Şehzade Camii, from the original Persian شاهزاده Šāhzādeh, meaning "prince") is a 16th-century Ottoman imperial mosque located in the district of Fatih, on the third hill of Istanbul, Turkey. It was commissioned by Suleiman the Magnificent as a memorial to his son Şehzade Mehmed who died in 1543. It is sometimes referred to as the "Prince's Mosque" in English. In a June 2016 attack, the windows of the mosque were shattered.

The Aqueduct of Valens (Turkish: Valens Su Kemeri, Ancient Greek: Ἀγωγὸς τοῦ ὕδατος, romanized: Agōgós tou hýdatos, lit. 'aqueduct') was a Roman aqueduct system built in the late 4th century AD, to supply Constantinople – the capital of the eastern Roman empire. Construction of the aqueduct began during the reign of the Roman emperor Constantius II (r. 337–361) and was completed in 373 by the emperor Valens (r. 364–378). The aqueduct remained in use for many centuries. It was extended and maintained by the Byzantines and the Ottomans. Initially, the Aqueduct of Valens carried water from springs at Danımandere and Pınarca; the channels from each spring met at Dağyenice. This 4th-century first phase of the system was 268 kilometres (167 miles) long. A second, 5th-century phase added a further 451 kilometres (280 miles) of conduits that took water from Vize, 120 kilometres (75 miles) away from Constantinople.: 13 The final and most visible aqueduct bridge in the system survives in the Fatih district of Istanbul, Turkey. Named in Turkish: Bozdoğan Kemeri, lit. 'Aqueduct of the Grey Falcon', it is an important landmark in the city, with its arches passing over Atatürk Boulevard (Atatürk Bulvarı). The Bozdoğan Kemeri spans the valley between the hills that are today occupied by the Istanbul University and the Fatih Mosque, formerly the site of the Church of the Holy Apostles. The surviving section is 921 metres long, about 50 metres less than the original length.

The Aviation Martyrs' Monument (Turkish: Hava Şehitleri Anıtı or formerly Tayyare Şehitleri Abidesi), located in Fatih district of Istanbul, Turkey, is a memorial dedicated to the first soldiers of the Ottoman Airforce to be killed in flight accidents. In Turkey, one use of the term "martyr" is as an honorific for people killed in action during war. The monument was commissioned right after the consecutive crash of two monoplanes in Palestine, killing three of the four military aviators who were on an expedition flight from Istanbul to Alexandria in early 1914. The monument, in form of a column, was inaugurated in 1916. A military memorial ceremony is held in front of the monument every year on Martyrs' Day.

The Church of St. Polyeuctus (Greek: Ἅγιος Πολύευκτος, translit. Hagios Polyeuktos; Turkish: Ayios Polieuktos Kilisesi) was an ancient Byzantine church in Constantinople (now Istanbul, Turkey) built by the noblewoman Anicia Juliana and dedicated to Saint Polyeuctus. Intended as an assertion of Juliana's own imperial lineage, it was a lavishly decorated building, and the largest church of the city before the construction of the Hagia Sophia. It introduced the large-scale use of Sassanid Persian decorative elements, and may have inaugurated the new architectural type of domed basilica, perfected in the later Hagia Sophia. Little is known of the church's history after its construction. The building survived until the 11th century, after which it fell into decay, while several architectural elements were removed and reused in Constantinople and other cities. After being built over in the Ottoman period, the site of the church was rediscovered during excavations in the 1960s. The area, directly opposite the Istanbul Metropolitan Municipality City Hall, is now a preserved archaeological site open to visitors, although the sculptures have been removed to the Istanbul Archaeological Museum.

Balaban Aga Mosque (full name in Turkish: Balaban Ağa Mescidi, where mescit is the Turkish word for a small mosque) was a mosque in Istanbul, Turkey, converted from a former Byzantine building. Its usage during the Byzantine era is unclear. The small edifice - pulled down in 1930 to open a new road - was a minor example of architecture of the Byzantine early period in Constantinople.