A novelist, biographer and essayist, Constantin lived ten years in Canada (Manitoba) between 1904 and 1914 and this adventurous period fed a big part of his later work written in France between 1920 and 1950. Maurice Constantin-Weyer was a successful writer, best known for his
novels of adventure: the most emblematic is Un homme se penche sur son passé (A man scans his past), which won the Prix Goncourt in 1928, and whose action takes place in large areas of the Prairie and northern Canada in the early twentieth century.
He returned to France in 1914 to fight in World War I, where he was often wounded and decorated (Verdun – Salonique...). After the war he became a journalist and published novels and biographies in France.
His original last name was only "Constantin"; he added the name of his second wife in 1920 and signed all his works Maurice Constantin-Weyer.