If I could answer this I would have completed the £500 Christmas prize crossword - could they have erred?
I think you are asking about Istanbul, but Istanbul was never a capital of independent Turkey. Atatürk moved the capital from Istanbul to Ankara early in his reign as Turkish President.
constantinople
The Capital of the Ottoman Empire was originally called Byzantium before being renamed as Constantinople and was renamed by Ottomans as Istanbul. It's says in my history book...: The victorious sultan rode to Hagia Sophia, the city's largest Christian church. There he offered thanks to Allah and gave orders that the church be transformed into a mosque. He decreed that Constantinopole was now a Muslim city, the capital of a Muslim empire, and renamed it Istanbul. The Byzantine Empire was no more. The Ottoman Empire no longer exists, its capital was Istanbul. The capital of modern Turkey is Ankara. Edirne was the third capital city of the Ottoman Empire, before Constantinople
Angora
the largest capital and former capital of turkey The name is derived from the Greek "Ein ten polin" (into the city)
Constantinople is the former name of the city of Istanbul which is the capital of Turkey. The name change was after the Republic of Turkey was established in 1923.
It is the capital of Turkmenistan. (transliterated from Russian, the spelling is Ashkhabad).
The present capital of Pakistan is Islamabad and its former capital was "Karachi".
The capital city of Turkey is Ankara. It is important to note that Turkey is not divided between Europe and Asia (in terms of subnational regions). The region with the entirety of Europe in it is the Marmara Region which also has areas from northwest Anatolia (with roughly the same area). This region, however, is cultural, as opposed to administrative and therefore has no capital. Istanbul does serve as capital of Istanbul Province, which is on both sides of the Bosporus. See the related link for an image of the Marmara Region.
Constantinopole was the former capital of the Byzantine Empire.
Edo is the former name for Tokyo, present capital of Japan
Turkey