The Byzantine Empire, also referred to as the Eastern Roman Empire, or Byzantium, was the continuation of the Roman Empire in its eastern provinces during Late Antiquity and the Middle Ages, when its capital city was Constantinople (modern Istanbul, formerly Byzantium). It survived the fragmentation and fall of the Western Roman Empire in the 5th century AD and continued to exist for an additional thousand years until it fell to the Ottoman Turks in 1453.
- Constantinople was full of inventors and craftsmen. The "philosopher" Leo of Thessalonika made for the Emperor Theophilos (829–42) a golden tree, the branches of which carried artificial birds which flapped their wings and sang, a model lion which moved and roared, and a bejewelled clockwork lady who walked. These mechanical toys continued the tradition represented in the treatise of Heron of Alexandria (c. A.D. 125), which was well-known to the Byzantines.
- J. R. Partington, "A History of Greek Fire and Gunpowder"(1999). The Johns Hopkins University Press. p. 13.
- The Byzantine Empire became a theocracy in the sense that Christian values and ideals were the foundation of the empire's political ideals and heavily entwined with its political goals.
- The constitution of the Byzantine Empire was based on the conviction that it was the earthly copy of the Kingdom of Heaven. Just as God ruled in Heaven, so the Emperor, made in his image, should rule on earth and carry out his commandments ... It saw itself as a universal empire. Ideally, it should embrace all the peoples of the Earth who, ideally, should all be members of the one true Christian Church, its own Orthodox Church. Just as man was made in God's image, so man's kingdom on Earth was made in the image of the Kingdom of Heaven.
- Steven Runciman, Runciman 2004, pp. 1–2, 162–63.
- It was the Byzantine Empire, which was to realize Alexander's idea - Macedonian Panhellenism -in face of an Asia in revolt, and realize it for the Greeks.
- René Grousset, A. Patterson, "The Sum of History", p. 159.
- Tell the your emperor; Where my power has reached, Emperor's dreams can not reach!
- The Christians were probably better off as dhimmis under Muslim-Arab rulers than they had been under the Byzantine Greeks.
- William Montgomery Watt, Islamic Political Thought: The Basic Concepts, p. 51.