This reflected its status as the only major city in the vicinity.
The importance of Constantinople in the Ottoman world was also reflected by its Ottoman name 'Der Saadet' meaning the 'gate to Prosperity' in Ottoman.
As the eastern capital of the empire, the city was named Nova Roma; most called it Constantinople, a name that persisted into the 20th century.
On 11 May 330, Constantinople was proclaimed the capital of the Roman Empire, which was later permanently divided between the two sons of Theodosius I upon his death on 17 January 395, when the city became the capital of the Eastern Roman (Byzantine) Empire.
The first use of the word "Islambol" on coinage was in 1703 (1115 AH) during the reign of Sultan Ahmed III.
Nevertheless, the use of the name Constantinople remained common in English into the 20th century, Istanbul became common only after Turkey adapted the Latin alphabet in 1928 and urged other countries to use the city's Turkish name.
An alternative view is that the name evolved directly from the name Constantinople, with the first and third syllables dropped.
because the city was called Islambol ("plenty of Islam") or Islambul ("find Islam") as the capital of the Islamic Ottoman Empire.
Some Ottoman sources of the 17th century, such as Evliya Çelebi, describe it as the common Turkish name of the time; between the late 17th and late 18th centuries, it was also in official use.By the 19th century, the city had acquired other names used by either foreigners or Turks.Europeans used Constantinople to refer to the whole of the city, but used the name Stamboul—as the Turks also did—to describe the walled peninsula between the Golden Horn and the Sea of Marmara.Overlooked for the new capital Ankara during the interwar period, the city has since regained much of its prominence.The population of the city has increased tenfold since the 1950s, as migrants from across Anatolia have moved in and city limits have expanded to accommodate them.
Founded under the name of Byzantion (Βυζάντιον) on the Sarayburnu promontory around 660 BCE, the city developed to become one of the most significant in history.