Nikolai Ivanovich Lobachevsky, an outstanding Russian mathematician, known as the creator of non-Euclidean geometry. His innovative ideas were not recognized during his lifetime, but their significance was confirmed after his death.

Lobachevsky was born on November 20, 1792, in Nizhny Novgorod. His father, an official in the geodetic department, died when Nikolai was only 7 years old. Due to financial difficulties, the family moved to Kazan. Nikolai studied at a local gymnasium and then at Kazan University, graduating with honors in 1811 with a degree in physics and mathematics.

In 1814, with the support of scholars Bronner and Bartels, Lobachevsky became an adjunct in pure mathematics, and two years later, an extraordinary professor. He taught algebra, trigonometry, geometry, and higher mathematics. In 1819, Lobachevsky became the dean of the physics and mathematics faculty at Kazan University and wrote several textbooks that were not immediately recognized by his contemporaries.

In 1827, he took the position of rector of the university and implemented significant reforms, including the construction of new buildings and the establishment of an astronomical observatory. His scientific discoveries were based on a critique of Euclid's parallel postulate, and he proposed his theory of the parallelism of lines. In 1832, he published the work "On the Foundations of Geometry," and in 1837, "Imaginary Geometry," which attracted the attention of Gauss.

Recognition of his non-Euclidean geometry came 12 years after his death, thanks to the Italian mathematician Beltrami. Among his other achievements were methods for approximate solutions to equations and theorems on trigonometric series.

Lobachevsky was awarded numerous honors, including the Orders of Saint Vladimir and Saint Anna, and he received nobility. In 1855, he became an honorary member of Moscow University.

After 30 years of service, Lobachevsky was removed from teaching and demoted, leading to financial difficulties. The death of his son in 1852 undermined his health, and he passed away on February 24, 1856. His works were recognized 12 years after his death, and universities, streets, and scientific institutions were named in his honor.