Outstanding mathematician of Alexandria, author of what may well be the second most influential book in Western culture: the Elements. Little is known about Euclid himself, and it is not clear to what extent the book describes original work and to what extent it is a textbook. The Elements develops a large section of elementary geometry by rigorous logic starting from assumed axioms. It includes his proof that there are infinitely many primes, the Euclidean algorithm, the derivation of the five Platonic solids, and much more. It served for two millennia as a model of what pure mathematics is about.

https://mathshistory.st-andrews.ac.uk/Biographies/Euclid/ A fuller biography of Euclid.