Pythagoras (circa 570-495BC) Mystical leader and number-obsessive, he owes his standing as the most famous names in maths due to a theorem about right-angles triangles. He lived in a community where numbers were venerated as much for their spiritual qualities as for their mathematical ones. His elevation of numbers as the essence of the world made him the towering primogenitor of Greek mathematics, essentially the beginning of mathematics as we know it now.
Hypatia (cAD 360-415) was a Greek woman mathematician and philosopher. Hypatia was a scholar at the library in Alexandria in the 4th century AD. Her most valuable scientific legacy was her edited version of Euclidi's The Elements, the most important Greek mathematical text.