This document provides brief biographies of several important mathematicians throughout history, including Pythagoras, Aristotle, Euclid, Al-Khwarizmi, Leonardo da Vinci, Galileo Galilei, De L'hopital, and Leonhard Euler. It notes the dates and places they lived, as well as some of their key contributions to mathematics such as Pythagoras' theorem, Euclid's Elements, Al-Khwarizmi's work on algebra, and Euler's work in calculus, geometry, and trigonometry.