In the year 656 of the Hijra, a woman named Zahra
copied a treatise on the movement of stars.

She worked in a city that had translated Aristotle,
Euclid, and Galen while Europe forgot how to read.

Astronomy Medicine Algebra Optics Philosophy Geography Poetry Chemistry Translation History

This is the inventory of what the world knew.

DAY 1
17 Muharram 656 AH

Baghdad's libraries held hundreds of thousands of manuscripts.

The number that survived: unknown.

The river, it is said, ran black for three days.

Euclid's Elements — survived in Latin translation from the Arabic.
Al-Khwarizmi's algebra — the word "algorithm" is his name.
Ibn al-Haytham's optics — shaped the science of sight for 600 years.
Galen's medicine — returned to Europe via Arabic translators.

What survived did not survive because of Baghdad.
It survived because someone, somewhere else, had made a copy.

You learned algebra in school.
That's what survived.

Sources

Primary Sources

Modern Scholarship