To these two passions, I would add a taste for Adventure—but not a solitary adventure, no! An adventure to be shared and passed on. Gilles had ideas, a wealth of ideas; he knew how to sow their seeds and sometimes entrusted others with helping them grow. One of those ideas, the one I am about to tell you about, is a perfect example. In 1993, Gilles founded the CIJM (International Committee of Mathematical Games) to forge links with the federations organizing the International Championship of Mathematical and Logical Games, which he had created in 1987. The CIJM then brought together mathematics competitions, rallies and tournaments that blossomed throughout France and the French-speaking world during the final quarter of the 20th century. This enabled all its member associations to pursue their aims more effectively, as summed up in the motto proposed by Gilles: "Together, we are stronger in inspiring a love of mathematics." In 1993, the Limousin Mathematics Tournament was itself 16 years old, and it immediately answered the CIJM's call… This marked the beginning of my collaboration with Gilles. The year 2000 was World Mathematical Year! The City of Paris issued a call for projects to celebrate mathematics! Gilles immediately saw an opportunity to launch the CIJM on a great adventure and assert its recreational and cultural mission. I will never know whether Gilles, visionary that he was, imagined that this "mathematical games fair," conceived simply as a celebration for the year 2000, would twenty-five years later become the annual Mathematics Culture and Games Fair, as the French Ministry of National Education calls it—too often forgetting that the fair is sustained not by passing fashions but by an enormous amount of volunteer work! At that point, in 1999, Gilles had to turn this idea into reality: staging a mathematics fair for the general public. Nothing mattered more to him, but success was far from assured. So Gilles boarded the Capitole train to Limoges, where he set out to convince a group of friends that the CIJM must—and could—embark on this project, which was far from universally understood or accepted. Gilles had initially thought of holding it at the Parc Floral in Vincennes, but thanks to a series of fortunate encounters ("encounters," the magic word for the fair!), it ultimately found a home on Place Saint-Sulpice, in the heart of Paris. For hundreds of years, this square has hosted Paris's oldest fair, the Foire Saint-Germain, each spring. The "mathematics fair" appeared on the program alongside fairs devoted to poetry, theatre, antiques, rare books and ceramics! What better setting could there be for celebrating the universality of mathematics? That first fair contained all the seeds of what we would later develop. Just look: \- A tremendous variety of stands: board games, hands-on activities, brain games, magic, astronomy, associations and the Palais de la découverte… \- An unforgettable Paris mathematics rally, requiring an incredible feat of organization! \- A Euromath competition, a spectacular mathematics show held in the reception hall of the 6th arrondissement town hall, with two young and elegant presenters: Audrey Candeloro and Jean-Christophe Novelli; \- And, to top it all off, a one-man show about zero by Denis Guedj.
The fair was a resounding success and could not remain a one-off event; expectations among educators, the research community and the general public were so high that we owed it to them to continue. Gilles placed his trust in the CIJM: to carry on the work while respecting the fair's guiding principle—creating a free, intergenerational, interdisciplinary and intercultural meeting place; and to develop the fair around three major ideas: the fair is a place where visitors can discover our discipline and its cultural roots; it is a place of creativity and innovation; and it is a space for meeting and exchanging ideas.
Every year, staging the fair was a real challenge. It also spent several years in exile. Fortunately, it benefited from the strong support of many friends. In 2011 and 2012, thanks to Cédric Villani, the fair moved into the galleries of Pierre-et-Marie-Curie University on Place Jussieu. In 2013, Claudie Haigneré made the forecourt of the Cité des sciences et de l'industrie available. In 2014, to everyone's great delight, the fair returned to its original setting: Place Saint-Sulpice. Throughout those years, Gilles, you and all the teams at Tangente and Tangente Éducation were the fair's most faithful partners. Since 2019, Animath and a consortium of thirteen associations and foundations have taken charge of organizing the fair and assumed financial responsibility for it. Animath's digital expertise enabled the fair to weather the two bleak years of lockdown by creating a "deMATHerialized" fair. Since 2022, the fair has not only returned to Place Saint-Sulpice but has also reached farther afield through its website, salon-maths.fr.
You see, Gilles, you were right to envision a Mathematics Culture and Games Fair because, as Mickael Launay puts it so well in his book Le Grand Roman des maths (Flammarion, 2016): "Mathematics has tremendous potential to become a festive and popular discipline." The adventure continues, Gilles; you will be with us in spirit at the twenty-fifth fair next May. It is up to all of us, and especially the youngest among us, to continue along the path you laid out. Thank you, Gilles!!