Nikolai Ivanovich Lobachevsky (December 1, 1792 - February 24, 1856) was a mathematician from Russia. He was known for his significant work on Hyperbolic geometry, also known as Lobachevskian geometry.
Before him, mathematicians tried to deduce the fifth postulate from other axioms. Instead he developed a geometry where the fifth postulate was not true. Thus creating Hyperbolic geometry.
