Constantinople for thousand years was the "Queen of cities=Basileuousa".
Rome collapsed under the pressure of the Germanic invaders in 476. In 5th century the state's control passed to Greeks and Greek language became the official language. Thanks to its greater military and economic strength, Constantinople survived for a thousand years, despite revolutions, wars, and religious controversy. Preserved the greek-orthodox civilization, fighting Bisigoths, Ostrogoths, Huns, Bandals, Persians, Arabs, Abars, Petzeneks, Slavs, Bulgarians, Francs, Benetians, Normands, Turks, Algerian pirates, Catalans.
Constantinople had a population of 1000000 habitants while the second largest city in Europe had 50000. Unlike Rome, Constantinople had several industries producing luxury goods, military supplies (the famous greek fire), hardware, textiles and jewellery. In about 550 A.D., after silkworms were smuggled out of China, silk protection became a highly profitable industry. The state paid very close attention to business controlling the economy; which is a system to which all tradesmen and members of the professions set wages, profits, work hours, and prices while bankers and doctors were organized into corporations. Security and wealth encouraged an active political, cultural, and intellectual life. The widespread literacy and education among men and women of various segments of society would not be matched in Europe until, perhaps, eighteenth-century France.
According to historian of 4th crusade Robert De Clari, Byzantium had accumulated the 2 thirds of whole world's property. In the City=Eis tin Polin=Istanbul (Constantinople) there were 4388 palaces, many hospitals, orphanages, poorhouses, thousands of churches and University called "Pandidaktirion"that was founded on 849 A.D. by Kaisar Barda. Other Universities were built in Antioxeia, Alexandreia, Athens, Thesalonica, Byrut and Kaesareia of Cappadokia.
Great astronomers were Proklos (410-485), Marinos (5th century), and Simplikios (6th century). Proklos used big lenses and burned the fleet of Goths in the port of Constantinople. Great architects were Isidoros from Militos and Anthemios from Traleis (Aydin). They designed and constructed the church of Ayia Sophia in 535 A.C, the greatest church ever built. Olny a thousand years lated the latins built a church of same magnificence in Rome. Leon from Thesalonica was a brilliant mathematic. Chalif Mamoun invites him in Granada-Spain to teach mathematics, offering to him 2000 livres gold. He refuses to go as he says to offer his services to enemies of his faith. The byzantine civil Law (Justinian codex) was the basis of the later European civil Law. On 726, Leo III Isaurian abolished the slavery in the farms. The farmers should be free men.
John II Comnenos (1118-1143) abolished the tortures and the death penalty. West Europeans learned from Byzantines how to eat not with hands but with forks, and to sleep in silk sheets. In 10th century Heron wrote a book about geodaecy. In 11th century Michael Psellos taught Law, Philosophy and Mathematics. He wrote also History. In 1241 in Nicaea of Mikra Asia, Nikiforos Blemmides wrote books about Astronomy, Mathematics and Philosophy. In 13th century Theodoros Metoxites was astronomer, and civil engineer and also Nikiforos Grigoras, Issac Argyros, Theodoros Melitiniotes and Georgios Paximeres. In 14th century lived mathematics Maximos Planoudes, Emmanouel Mosxopoulos, Nikolaos Ravdas and monk Barlaam from Kalavria-Italy. In Trapezous - Pontus, Gregorios Chioniades and Konstantinos Loukitis taught mathematics and astronomy.
In 15th century many valuable books, manuscripts, icons and trasures were moved to Italy, to be saved from the turkish invaders. One of the greatest personalities was philosopher Georgios Plethon (1360-1452). He wrote philosophy, geography, history and many more. He was deeply influenced from the spirit of Socrates, Platon and Aristoteles. The creation of the Cyrillic alphabet for the Slavs by Byzantine missionaries Cyril and Methodios, and the preservation of ancient Greek manuscripts and culture by Byzantine scholars were among the most important contributions of the Byzantine Empire to european posterity.
In 1453 books, manuscripts, icons, buildings, and works of centuries were turned to ashes in some hours. But byzantine intellectual tradition did not die in 1453: Byzantine scholars who visited Italy as individuals or imperial envoys in the 14th and 15th centuries exerted a strong influence on the Italian Renaissance.
Latins called it "Center of World", Turks called it "Kizil Elmas", Scandinavs "Miklegarth",
Russians "Tsarigrad", and
Arabs called it "Dar Es Saadet". Turks now name it "Istanbul" which comes from the greek words
"Eis tin Polin", which means "to the City". Greeks used to call their capital "Polis=City".