Non-Euclidean geometry

Non-Euclidean geometry is a type of geometry that rejects the common Euclidean postulate that only one line can be drawn parallel to a given line through a given point not on the line. Its development showed that new consistent geometries could exist outside of the traditional Euclidean framework, significantly impacting the field of mathematics.
 Nikolai Ivanovich Lobachevsky and János Bolyai Russia and Hungary 1826 Non-Euclidean geometry

Non-Euclidean geometry is a type of geometry that rejects the common Euclidean postulate that only one line can be drawn parallel to a given line through a given point not on the line. Its development showed that new consistent geometries could exist outside of the traditional Euclidean framework, significantly impacting the field of mathematics.