Pierre de Bélay was born in Brittany, a region that regularly returns in his oeuvre in the form of Breton fishing scenes and harbour views. He also painted performances with the city and theater life of Paris as the subject. In 1919, at the age of 29, he had settled in the French capital. His favourite neighbourhood was Montparnasse, which around that time took over Montmartre's role as a nighttime entertainment center and artists' quarter. From 1923 to 1926, De Bélay was an illustrator for the cultural magazine 'Harlequin'. He then developed into one of the most in-demand painters of Parisian nightlife.