**Lélio Gama** lived most of his life in Rio de Janeiro. He was Full Professor of Mathematical and Higher Analysis at Univ. Federal District (1935-38) and the University of Brazil (1939). Received the title of member of the Brazilian Academy of Sciences.

It had its professional beginning in 1929, with Astronomy. During this period, Lélio built a solid reputation as a talented scientist with great resourcefulness in the techniques of classical mathematics, publishing several works on Mathematical Astronomy and Celestial Mechanics: problems in determining latitude, the oscillation of the earth's axis, the movement of asteroids, etc. .

Its first mathematical phase was from 1935 to 1939. In 1935, the Federal District University in the city of Rio de Janeiro was established, and Lélio Gama was invited to work as a mathematics teacher at the School of Science.

During the three years of existence of this university, he taught there, with great success and audience, several Mathematical Analysis courses which, besides having a masterly clarity, dealt with both theoretical aspects and the most current in the subject, such as Functional Analysis a Fréchet, Topology a Sierpinski & Kuratowski, etc., with what Brazil has entered into twentieth-century mathematics, as more practical and technical topics, as a rather technical Infinitesimal Calculus Course based on Du Bois Raymond's notion of asymptotic scales.

It is noteworthy that the publication of these courses allowed their use not to be restricted to Rio de Janeiro teachers and advanced students. In 38, this university became extinct and gave rise to the University of Brazil (later called the Federal University of Rio de Janeiro). Lélio continued his work at the Faculty of Philosophy of this, unfortunately only for a year (1939), at the end of which he left aside mathematical studies and began to devote himself to a long international project of astronomy.

His second mathematical phase was from 1952 to 1962. In 1950, Admiral Alvaro Albert - professor at the Naval School - represented Brazil at the United Nations Atomic Energy Commission. Impressed by the potential of this technology, he returned to raise awareness among government authorities of the need to prepare scientists and set up laboratories to be able to study and exploit this energy. The Presidency of the Republic appointed a commission to outline a march of action and this resulted in the creation of the CNPq (1951: National Research Council).

Among the various high-level scientific institutions created around CNPq was IMPA (1952: Institute of Pure and Applied Mathematics, RJ), which had the task of developing high-level research and giving postgraduate courses in mathematics. Its first director was Lélio Gama, who held this position for 10 years, with the task of building the foundations of this institution. Under the guidance of Lélio, IMPA had had a modest departure (started with only three researchers, all of great talent: Leopoldo Nachbin, Maurício Peixoto and Paulo Ribenboim). Gradually, it has become a center capable of influencing mathematics throughout Brazil and is now a renowned institution of international standard.**.**