Euclid is considered the father of geometry. He was a Greek mathematician active in Alexandria around 300 BC, and his most famous work is "Elements," a comprehensive compilation of the knowledge of geometry of his time. In "Elements," Euclid systematically presented geometric concepts, defined fundamental terms, and provided rigorous proofs for various theorems, forming the basis of what we now call Euclidean geometry. His logical approach and methodical presentation influenced mathematics for centuries and is still taught in schools today. Euclid's work laid the groundwork for advanced mathematics and geometry, earning him a lasting legacy in the field.