1020 – 1030s

Events in the 1020s 5

• 610 – 1025 The Middle Period (610–1025) The Middle Byzantine period spans from Heraclius's accession to the death of Basil II the Bulgar-Slayer. It encompasses the catastrophic loss of Syria, Palestine, Egypt and North Africa to the Arab conquests, the iconoclasm controversy that splits the empire for over a century, the conversion of the Slavs and Bulgars to Orthodox Christianity, and the Macedonian dynasty's military and cultural renaissance. The period ends at Byzantine apogee under Basil II, when the empire controls more territory than at any time since Justinian.
• 976 – 1025 Basil II -- the Bulgar-Slayer at Byzantine apogee Basil II (976-1025) is the greatest military emperor of the middle period. He destroys the Bulgarian Empire, blinding 15,000 Bulgarian prisoners (leaving one eye to every hundredth man to lead the others home), reconquers Syria and Georgia, and converts the Rus of Kiev to Orthodox Christianity through the baptism of Vladimir I. At his death the empire is at its largest extent since Justinian.
• 1011 – 1021 Ibn al-Haytham — Book of Optics Light travels to the eye, not from it — the birth of experimental science Between 1011 and 1021, while under house arrest in Cairo, the Iraqi scholar Ibn al-Haytham (Alhazen) wrote his seven-volume Kitab al-Manazir (Book of Optics). He proved by experiment that vision occurs because light reflects from objects into the eye — overturning a thousand-year-old belief that the eye emits light. He described accurately the anatomy of the eye, explained refraction, and invented the camera obscura. His rigorous experimental method was centuries ahead of its time and directly influenced Roger Bacon, Leonardo da Vinci, and later Kepler and Descartes.
• 1025 – 1261 Decline & The Crusades (1025–1261) The period from Basil II's death to the Nicaean reconquest of Constantinople spans the catastrophic defeat at Manzikert (1071), the loss of Anatolia to the Seljuk Turks, the complex and often damaging relationship with the Crusader states, and the catastrophe of 1204 when the Fourth Crusade sacks Constantinople and establishes the Latin Empire. The Nicaean Empire -- the Byzantine government in exile -- reconquers Constantinople in 1261 under Michael VIII Palaiologos, but the empire it restores is a shadow of its former self.
• 1026 – 1033 Guido of Arezzo Italian music theorist and pedagogue Guido of Arezzo was a medieval music theorist whose innovations in notation and solmization formed the foundation of Western musical education. He developed the staff system and the hexachord system used to teach sight-singing.