Isidore of Miletus

Content sourced from Wikipedia, licensed under CC BY-SA 3.0.

Isidore of Miletus was a Byzantine scientist and architect who helped design Hagia Sophia in Constantinople for Emperor Justinian I. He was born around 475 AD and became a noted mathematician, physicist, and builder.

Together with Anthemius of Tralles, Isidore planned and oversaw Hagia Sophia, built between 532 and 537. It was one of the grandest churches of the time, designed to be strong against earthquakes and fires. Isidore and Anthemius gathered materials from across the empire, including stone from faraway places and columns from Roman temples. The building combined the layout of a Roman basilica with a central domed space, creating a striking and harmonious structure.

Isidore was also a key scholar. He edited and commented on earlier Greek works and helped create the first major collection of Archimedes’ writings, known from the Archimedes Palimpsest that survives today. He revised parts of Euclid’s Elements, and some scholars once attributed Book XV of Euclid to him, though that attribution is uncertain. He taught stereometry (a form of geometry) and physics in Alexandria and later in Constantinople, and wrote a commentary on Hero of Alexandria’s On Vaulting, a work about vault construction and geometry. He is also said to have designed a special compass for drawing parabolas, which improved the accuracy of vault drawings and helped with problems like doubling the cube.

There is debate about a “School of Isidore,” a idea that Isidore’s teaching influenced later mathematicians. This view relies more on his students’ works than on his own writings, since Isidore did not publish much himself. Nevertheless, his teaching is believed to have helped revive interest in ancient mathematics in Constantinople and Alexandria around that time.

About Hagia Sophia, after the Nika Riots in Constantinople, Justinian wanted a church that could endure. The dome and vaults were advanced for their time, and Isidore’s expertise in vaulting likely shaped much of the work. The dome was originally built without ribs, but later received a ribbed reconstruction by Isidore’s nephew, Isidore the Younger. After a major earthquake in 989, Trdat the Architect was called to Byzantium to repair the structure, completing the restoration by 994. Hagia Sophia remains a lasting testament to Justinian’s ambition and to Isidore’s mathematical and architectural influence.