Constantinople was the name of the city corresponding to present-day Istanbul, from 324 until it officially was renamed Istanbul in 1930. The city never really had the name Constantinople, but the name was popularly used by people in remembrance of its founder, Emperor Constantine.
For now, the current article on Instanbul covers the long history of Constantinople.
324: Celebrating his victory against the eastern Roman Emperor, Licinius, Constantine 1 has Byzantium renamed Nova Roma. Gradually, however, the popular name would become Constantinople.
330 May 11: Roma Nova becomes the seat of the Roman Empire, and is formally named after Constantine the Great, to Constantinople.
381: A patriarchate is established in Constantinople, second only to the Pope in Rome.
Early 5th century: New city walls are erected, and are the ones surviving until modern times.
532: Large parts of the city is burned and about 30,000 of the population is killed during a repression of an insurrection.
537: The Hagia Sophia church is completed, the most magnificent building of its time.
542: A plague kills about 75% of the inhabitants of Constantinople. The effects were devastating, and weakened the city and the Byzantine Empire for 300 years.
626: Is besieged by Persians and Avars, but withstands.
674: Is besieged by Muslim Arabs, a siege that would last for 5 years, but without the fall of Constantinople.
717: A second siege by Muslim Arabs, this time lasting 2 years, but again without the fall of Constantinople.
813: Bulgars besiege Constantinople, but it withstands.
813: Russians besiege Constantinople, but it withstands.
913: Bulgars besiege Constantinople for a second time, but the city withstands.
941: Russians besiege Constantinople for a second time, but it withstands.
1043: Russians besiege Constantinople, but it withstands again.
1054: The Great Schism divides Christendom in an western and eastern part, with Constantinople as centre of the eastern.
1090: Turkic Pechengs try to conquer Constantinople, but without success.
1203: Captured by the armies of the 4th Crusade, but the city remained under its own rule.
1204 April 13: Crusaders burst into Constantinople, and sacks the city, and plunders all its wealth. They established a Latin rule, while the Byzantine Empire continued to exist with its capital in Nicaea 100 km southeast.
1261: Constantinople is conquered by Michael 8 Palaeologus, and reestablished as capital of the Byzantine Empire.
1422: Ottoman sultan Murad 2 lays a siege on Constantinople.
1452: Sultan Mehmed 2 lays Constantinople under siege, and erects a strong fortress at Rumeli Hisari effectively blocking the strait of Bosporus.
1453 May 29: Constantinople is captured by Ottoman troops, and is quickly turned into capital of the empire. The city was pillaged and its inhabitants massacred for 3 days, before order was established by the sultan.