Born René Georges Hermann Paul, he adopted the pseudonym Hermann-Paul. Trained at the Académie Julian, he also attended the École nationale supérieure des arts décoratifs. Both painter and illustrator, he was drawn to revolutionary and anarchist ideas, contributing illustrations to Émile Pouget’s Album du Père Peinard in 1898 as well as to various libertarian periodicals.
He was a prolific contributor to Le Sourire (1899–1914) and to L’Assiette au Beurre (1901–1912), the satirical journal to which Kupka and Van Dongen also contributed.
Of Provençal descent, he settled toward the end of his life in Saintes-Maries-de-la-Mer, where he became one of the region’s foremost painters and illustrators. At the request of the Marquis Folco de Baroncelli-Javon, he designed the Croix de Camargue, also known as the Gardian Cross, in 1924, a single emblem uniting the symbols of the three theological virtues: Faith, Hope, and Charity.