A renowned mathematician and engineer even before Justinian I commissioned him to build the Hagia Sophia in Constantinople, the Greek Isidore of Miletus had a storied career. He taught at the universities of Alexandria and Constantinople, made the first comprehensive compilation of the writings of Archimedes, and designed baths and temples. But it is the big basilica he is remembered for in civilization.

The first basilica on the site had been completed in 360 AD, but had been badly damaged in the Nika Riots – along with most of the rest of the city. The Nika Riots in 532 – sparked by clashes between the Blues and the Greens, supporters of rival chariot racing teams in the Hippodrome – left half the city burned and some 30 thousand dead. Justinian, a holy man, wanted a church that couldn’t be burned down. He turned to Isidore and to Anthemius of Tralles.

Their design drew upon classical Roman architecture and modern (for the time) construction methods; the basilica was centered on a 250-by-230 foot great hall capped with a massive dome, making it the largest church in the Orthodox realm. The Hagia Sophia was completed in just five years, due to the thousands of “volunteer” laborers and loads of raw materials “donated” by the empire’s subjects. Isidore likely died before 558, for when the dome was damaged in an earthquake that year, it was his nephew Isidorus who oversaw the repairs.