The capital of Byzantium, Istanbul (Constantinopolis) the most powerful centre at the decline of the W. Roman empire, became the centre stage of hundreds of years of sparkling growth, bloody struggles for power and various rebellions. Initially restricted within the Septimus Severus' walls, the city grew in waves expanding as far as the Theodosius walls. Hence, Constantinopolis, like ancient Rome became a city settled upon seven hills.

Here you will find links providing information regarding Constantinople, the Bizantine Empire and some monuments that have shared both Byzantine and Ottoman Empire:

From Constantiople to Istanbul (trying to understand history !) Mosaic Museum Saint Sophia Church Hyppodrome Underground Cistern City walls Kariye or Holy Church Maiden Tower Galata Tower