I wasn't quite sure that I wanted to do mathematics. There was often a greater urge to study literature.

I used to think of the book on game theory and the book on topology as a couple of false starts from the days before Claude found his true calling in graph theory and combinatorics. A computer search through Mathematical Reviews changed my mind: with each of these two books, Claude left a lasting mark on the subject. I was pleased to learn that the notions of 'Berge equilibrium' and 'Berge strategies' were being studied by game theorists thirty years after the publication of Claude's book; I was pleased to learn that the 'maximum theorem of Berge' and 'Berge upper semicontinuity' were being studied by economists thirty years after the publication of Claude's book on topology. I was pleased to read Mark Walker's words: "The maximum theorem and its generalizations have become one of the most useful tools in economic theory. The theorem - first stated, and proved by C Berge - gives conditions under which ...". It is amusing to speculate that, just as Claude Berge is a combinatorist to many of us combinatorists, he may be a game theorist to some game theorists and he may be a topologist to some economists.

Graph Theory has its origin in a great number of old problems (in the work of Euler, Kirchhoff et al.) and in recent years its range has become vastly greater. We draw a graph each time we want to represent by points a number of individuals, cities, chemical substances, strategic positions, and to join certain pairs of them by arrows, symbolizing a definite relationship. These diagrams are used in different fields under different names: sociograms (psychology), simplexes (topology), electrical circuits (physics), communication or transportation networks (operational research), family trees, etc. Thanks to the process of abstraction, which is so characteristic of twentieth-century mathematics, the properties of all these diagrams have been systematically analysed and a uniform theory has arisen which is applicable to all these fields.

... has had a major impact on the development of graph theory over the last 40 years. It has led to the definition and study of many new classes of graphs for which the strong perfect graph conjecture has been verified. Powerful concepts and methods have been developed to prove the strong perfect graph conjecture for these special cases. In this paper we survey 120 of these classes, list their fundamental algorithmic properties and present all known relations between them.

This group was created on 24 November 1960 ... Oulipo was a group of writers and mathematicians aiming at exploring in a systematic way formal constraints on the production of literary texts. Although poets had explored for years the formal constraints of versification, the originality of the group was to develop new or rarely studied constraints and to explore them systematically.

In our modern everyday life we are surrounded and bombarded by (too) beautiful, flawless pictures, sculptures and designs. In this stream Claude Berge's sculptures catch our attention, with their authenticity and honesty. They are not pretending to be more than they are. Berge catches again something general and essential, as he did in his mathematics. The sculptures may at first seem just funny, and they certainly have a humorous side. But they have strong personalities in their unique style - you come to like them as you keep looking at them - whether one could live with them if they came alive is another matter!

In 1956-57 he was research associate at Princeton University. He has participated in colloquia at Harvard University and the Massachusetts Institute of Technology and has lectured at a number of institutions in the United States, including Stanford University and the University of California, Berkeley.

The book is a classic in its area and has been instrumental in introducing mathematicians to graphs and taking them to the frontiers of current research.

The book presents many examples and applications, especially to integer programming and game theory, and every chapter is accompanied by exercises. The style and content of the book reflect throughout the influence of the author's own work and the distinctive flavour of his personal approach to the subject. The book is an excellent source for both student and researcher.

Berge was still alive when the news of the resolution of his more difficult conjecture came in, although he was reportedly very ill. He must have felt happy to see the end of this four-decade long adventure during his lifetime, although I do not think that the proof itself would have given him any great pleasure. Berge was very much a product of the old school and 'clean' and 'pretty' proofs mattered to him almost as much as the proof itself.

His residence at 10 rue Galvani in Paris' 17th arrondissement was like an unkempt museum with his own sculpture competing for space with the many Chinese works of art that he so adored. A visit to the Berge residence would find him curled up on a sofa, smoking his favourite pipe and gazing intently and lovingly at an 'objet d'art'. Being one of Berge's foreign students in France, it was my privilege to be invited to his house for Christmas dinners. I have the most wonderful memories of these dinners. Berge could either be in a good mood or sulking like a spoilt child. On one occasion he was inconsolable when his wife served us red wine that was excessively chilled. "It shouldn't be less than 18°C", he kept grumbling. Thankfully, his spirits improved a little after he found that the steak was done just right.

Mathematician, combinatorist, sculptor, amateur anthropologist, world traveller, collector of Indonesian art, Oulipist, chess player and player of exotic game pieces, author of manuals, professor renowned for his 30-minute lectures, 35-year member of the Centre de Mathématique Sociale, CRNS researcher emeritus at the EHESS until June 30, 2002: such was Claude Berge.