In her long history from her enlargement and renaming by Constantine the Great in 324 to 1453 when she was conquered by the Ottoman Turks, the city of Constantinople rapidly became the most important residence of the rulers of the Roman Empire. This was especially so in the period after 476, the year of Rome’s downfall and the western half of the Roman Empire. During these fourteen centuries the ‘polis of Constantine’ became the successor and heiress of the old centre of this vast Empire. Right from her ambitious beginnings, Constantinople was comparing herself with Rome: she wanted to be more than just another residence of the Roman emperor or only one of many new imperial foundations within the Roman Empire. To be looked at as respected and dominant as Rome, Constantinople saw herself as the most important city of the Roman (later East Roman, then Byzantine) Empire and the centre of the orthodox Christianity. The ambition of Constantinople to be the rival of Rome is shown by two names: Soon some of her admirers (pagan as well as Christian authors) called her the ‚Second Rome‘, not much later even the ‚New Rome‘. As ‚Second Rome‘ Constantinople was willing to pay tribute to Rome and to recognize the superiority of the only capital of the Roman Empire; as ‚New Rome‘ she claimed to be the new capital, the only existing successor and heiress of old Rome. By quoting and analyzing mainly Greek sources from the fourth to the sixth century, this essay presents contemporary statements, how Constantinople liked to be seen by her admirers: as a daughter of Rome or as her sister. This comparison expressed the self-esteem of Constantinople as an imperial and Christian city, but also had a decisive disadvantage: it reflected and accepted the existence of ‚Constantine‘s polis‘ in the shadow of Rome.