Euclid (c. 300 BCE) was an ancient Greek mathematician, often called the "father of geometry". His work, Elements, laid the foundation for Euclidean geometry, which dominated mathematics for nearly 2000 years.
Little is known about his life, but he likely studied at the Platonic Academy in Athens before teaching in Alexandria under Ptolemy I. His Elements synthesized earlier Greek mathematical knowledge, refining concepts from Eudoxus, Theaetetus, and Hippocrates of Chios. The treatise introduced an axiomatic system, logically deriving geometric theorems from basic postulates.
Beyond Elements, he wrote on optics, conic sections, and number theory. His influence extended beyond antiquity, shaping medieval Islamic, Renaissance, and modern mathematics. Though challenged by non-Euclidean geometries in the 19th century, his work remains fundamental in mathematics education.
Euclid's legacy endures through countless editions of Elements and his impact on logical reasoning and geometry. His name is now synonymous with classical geometry, and his contributions continue to shape mathematical thought.