Constantinople is in Turkey, is it not? That must be an awkward relationship. How have they not been disappeared off like the Nestorian Church.
They were a much larger minority until the Greek and Armenian Genocides (circa 1914-1923). It was Turkish nationalism, not Islamism, that was their doom.
Istanbul, not Constantinople.
The submitter used the title as published in the article.
In this case, Constantinople is short for "Patriarchate of Constantinople", which is still called that.