Constantinople was not taken by the Arabs. It was taken by the Ottoman Turks who established the Ottoman Empire
After the capital of the Roman Empire was moved to Constantinople, the Empire lasted over 1000 years.
It was a strategic move of the capital of the roman empire from rome to constinople. The high walls lasted from lots of invasions.
The Incas
Byzantium, later renamed Constantinople after him (polis = city in Greek, the language of the Eastern Roman Empire).
Arab Nationalism rose to prominence with the weakening and defeat of the (non-Arab) Ottoman Empire in the early 20th century and declined after the defeat of the Arab armies in the Six Day War.
Persian Empire
The Mongols Created such a huge empire by killing women and children, and wiping out armies, towns, and cities. They eventually ruled almost all of Asia and most of Europe.
The Austrian Empire.
It took them America 12 years to defeat Japan's Empire
The attack was no surprise - the two armies were confronting each other. Alexander wanted to defeat the Persian army to gain control of the Persian empire.
No empire was created specifically in order to conquer Constantinople. From 656-661 C.E. there was the Fitna al-Kubra or the First Islamic Civil War where the the Rightly-Guided Caliphate, the Khawarijites, and the Umayyad Caliphate all fought each other for dominance in Egypt, Levant, and Mesopotamia. The Umayyad Caliphate came out of that war as the single Islamic Empire and single Arab State. The Umayyads focused their attention northward and besieged Constantinople from 674-678 C.E.
Asians