Two exhibitions that were showing in Paris in 1934 produced a direct effect on Humblot’s development. At the Musée de l’Orangerie Les Peintres de la réalité en France au XVIIe siècle and at the Musée du Petit-Palais, Le Nain. During this period the ‘Ecole de Paris’ was made up of two distinct groups. On the one hand, there were those who loosely followed fauvism and cubism and on the other, those whose route could be best described as taking a tributary of impressionism. Humblot did not subscribe to either of these ideas and he forged another way, in which he sought to emulate the structure of the realist compositions epitomised by Georges de la Tour, the Le Nain brothers and the enigmatic Baugin. To this end, in 1935 he joined forces with two other pupils from the Atelier Lucien Simon, Georges Rohner and Henri Jannot to form a movement called Groupe Forces Nouvelles and he exhibited with them until 1939. They sought to portray reality in their art, both in its exterior form and in the thinking and ideas that created it. They gave their standpoint the lustre of a fight, and they were convinced that in the context of the era, a return to the greatness of tradition represented the most daring calling. Their principles fostered a return to drawing in the traditional manner, whilst engaging with the modern world and without isolating the group in academic preoccupations.

Humblot was taken prisoner but escaped in 1941 and went into hiding until the war was over. He did drawings in Germany and in the Tyrol, then rejoining the Oppède group, took refuge first in Villefranche-sur-Mer, then in the Auvergne and finally in the Forest of Fontainebleau.

At the Liberation in 1945, Humblot returned to Paris and mounted an Exhibition in the Galerie Barreiro where his work had already been showing for a year. A succession of important exhibitions followed. The next year he showed with Galerie Claude, and in 1947 he painted in Holland and exhibited at the Galerie Chabanon. In the same year the Georges de Braux Gallery showed his work in Philadelphia. He never had any interest in the Committees that presided over the Salons, although he exhibited at the Indépendants, the Salon des Tuileries and d’Automne and at the Salon des Peintres temoins de leur temps. When Galerie Framond opened in 1950 Humblot and Oudot were the first to unveil their latest work there. Humblot went back in 1951 and 1953 and added the Galerie Actuarius in Strasbourg to his triumphs in 1954. From 1955 until his death in 1962 Humblot stayed with Galerie Romanet in Paris, and held more shows abroad: in Geneva at the Musée de l’Athenée and in London at Tooth, both in 1957 and at Raphèle-les-Arles at La Jansonne in 1959, to name but the major shows