Grigori Yakovlevich Perelman, Russian mathematician, was born on June 13, 1966 in Leningrad, Soviet Union (today Saint Petersburg, Russia), son of Jewish parents.

He is known to have presented, in late 2003, a demonstration of the Poincaré conjecture (a particular case of the Thurston Geometrization conjecture), which was one of the most famous problems in mathematics.

The complexity of the subject led *Clay Mathematics Institute* to include the problem among the seven millennium problems. For each challenge that was solved, the institute promised to pay a prize of one million dollars.

Grigori Perelman presented the solution when he was under 40, becoming a strong contender for a Fields Medal, a sort of Oscar for mathematics.

He ended up being honored on August 22, 2006 at the International Congress of Mathematicians held in Madrid, but declined the medal. He also turned down the $ 1 million Clay Prize, claiming he was not a math hero, did nothing exceptional, didn't want to be watched, and had everything he wanted.

His mathematical talent was noticeable from an early age. He studied at Leningrad High School, which specialized in advanced math and physics programs. In 1982, as a high school student, he achieved the perfect score and won a gold medal at the International Mathematical Olympiad (IMO), representing the Soviet Union team.

Perelman has held research positions at several US universities. With a dissertation entitled "Saddle Surfaces in Euclidean Spaces", he received the title in the late 1980's "*Candidate of Sciences*"at the Leningrad State University School of Mathematics and Mechanics.

He worked in Aleksandrov's spaces of limited underside curvature, which earned him in the early 1990s the prize *Young Mathematician Prize*of the Mathematical Society of St. Petersburg.

He was then invited and began working on Ricci curvatures at the Courant Institute of Mathematical Sciences and New York State University. He also managed to prove Soul's conjecture in 1994.

From then on, he received several invitations to work at prestigious US universities such as Princeton and Stanford. However, he rejected the requests and in 1995 returned to the Steklov Institute in St. Petersburg for a research post.

After these refusals and controversies over his refusal to accept the prizes for the Poincaré conjecture solution, Russian newspapers reported that he had abandoned mathematics, retreating to almost total isolation, and living with his mother. Many argue that the main reason for Perelman's hurt was disagreement with the Steklov Institute where he worked.