Constantino Tsallis was born in Athens, November 5, 1943 during a very turbulent period in Greece. Emmanuel Tsallis and Cleopatra Yavassoglou, in the hope to give a better future for their three kids, Demetrio, Constantino and Thalia, decided to emigrate to South America. They arrived in Brazil in 1947, but one year later moved to Mendoza, Argentina.

Constantino grew up in this city located at the border of the Andes, "tierra del sol y del buen vino... y de las lindas mendocinas!" as says the song. His parents taught him to enjoy the diversity of the dances, the music, the culture, language and traditions, and other pleasures of life such as food and drinks found in different countries.

In 1960, he starts his life as a globe-trotter. He goes to San Juan to study at the Universidad Nacional de Cuyo. After studying two and half years of chemical engineering at Cuyo's University, he decided to move to a more competitive school and applied for a position as undergraduate student at the Instituto de Fisica Balseiro in Bariloche. Already during these early years of his career, Constantino demonstrated his tendency to challenge the principles of the fundamental theories. One of his colleagues from that period who is still working in Bariloche, Prof. Gert Lantschner, remembers Constantino's unusual reactions when the class was asked to find the solution of say the quantum square potential. Instead of directly solving, as everybody else, the Schroedinger equation for this potential, he systematically questioned the reasons behind the peculiarities of the equations themselves, why the factor i, why h, and so on.

In 1965, after getting his Master degree, at the age of 22, he decided to move again and do the Doctor degree abroad. Paris was his choice and he quickly became faculty of the University of Paris, simultaneously working for his Doctor degree, first through a quick incursion in experimental laser physics at the University of Paris, then theoretical physics at the CNRS / Bellevue, and then finally at Saclay. This research enabled him to get the doctor formal degree.

His move to Paris coincided with two revolutions, one in the intellectual thought with May 1968, and the other one in physics with the boom of the phase transitions and critical phenomena. It was the Paris of de Gaulle, CGT, Jean Paul Sartre, Simone de Beauvoir, Louis Aragon, Les Yeux d' Elsa, Juliette Greco, the Vietnam war protests, Picasso, but also it was the Orsay of de Gennes and Friedel. From them and from his old professor from Bariloche, Guido Beck, he learnt that science and life walk together. Even the most complicated theories do exist to explain real phenomena and that link should never be overlooked. He also learnt from them that it is possible to do theoretical physics without necessarily making long calculations. He got his '' Doctorat d' Etat es Sciences Physiques '' in 1974 at the Universite de Paris-Orsay. The president of the thesis committee, Prof. Andre Guinier, ended his presentation saying: "Monsieur Tsallis a du flair, il devinne les reponses".

In 1975 he moves to Brazil, first to Brasilia where he worked at the Universidade de Brasilia for two years, and after that to Rio de Janeiro, working at the Centro Brasileiro de Pesquisas Fisicas (CBPF) where he is today full professor. Acknowledging the at that time huge differences between the Brazilian northeast universities, where research was just starting, and the CBPF that had a fully working research program, he developed deep collaborations with the Physics Department of the universities in Natal and Maceio ( both in the northeast). Today, many of his former students and collaborators are in high positions in the research career. To improve the visibility of the statistical physics Brazilian community, he organized in Rio de Janeiro, in 1989, the 17th IUPAP International Statistical Physics Conference in Rio de Janeiro. He is also well known for keeping collaborations in many countries in Latin America such as Argentina, Chile and Mexico.

Even facing the funding difficulties shared by the scientists in Latin America, he has been able to sustain an intense participation in the international community.