On 2 September 1954 the International Congress of Mathematicians opened in Amsterdam. This is the largest mathematical conference in the world, held once every four years, at which the famous Fields medal is awarded. On the initiative of the ICM a large one-man exhibition on Escher was held in the Stedelijk Museum. The organising committee chaired by Amsterdam professor of Mathematics N.G. de Bruijn, put Escher on a pedestal as a unique link between art and mathematics.
The congress and the exhibition proved to be a boon for Escher in terms of putting him in contact with mathematicians. Congress attendees visited the exhibition in droves and were deeply impressed by it. Here, British mathematician Sir Roger Penrose and British-Canadian mathematician Donald Coxeter first came into contact with Escher’s work. Escher would maintain a warm contact with both and the artist and the mathematicians would continue to inspire each other. Coxeter gave Escher the idea for his circle limits. After seeing Relativity at the exhibition, Penrose, together with his father Lionel Penrose, published an article about impossible forms. The exchange of ideas between Escher and the Penroses would lead to the prints Waterfall and Ascending and Descending. Like Escher, Penrose has been fascinated by tessellations throughout his career
In the preface to the catalogue De Bruijn wrote about the playfulness with which Escher took on mathematics. A key point in understanding what fascinates mathematicians in their work. In the catalogue Escher himself wrote candidly (for the first time, in fact) about his own motives and his position as an artist. This was also the first time he labelled himself as an artist. During the congress he delivered a speech that was highly successful. The congress and the exhibition provided him with many new buyers. More importantly, they brought him friends in the mathematical community.