1850s. In French literature, Honoré de Balzac's ambitious La Comédie humaine, a set of nearly 100 novels, novellas and short stories with some recurring characters, started to come together during the 1830s. Émile Zola's Rougon-Macquart cycle is a family saga, a format that later became a popular fictional form, going beyond the conventional three-volume novel. A roman-fleuve (French, literally "river-novel") is an extended sequence of novels of which the whole acts as a commentary for a society or an epoch, and which continually deals with a central character, community or a saga within a family. The river metaphor implies a steady, broad dynamic lending itself to a perspective. Each volume makes up a complete novel by itself, but the entire cycle exhibits unifying characteristics. The metaphor of the roman-fleuve was coined by Romain Rolland to describe his 10-volume cycle Jean-Christophe. In the preface to the seventh volume, Dans la maison (1908/1909) he wrote: "When you see a man, do you ask yourself whether he is a novel or a poem? ... Jean-Christophe has always seemed to me to flow like a river; I have said as much from the first pages." The term has subsequently been applied to other French novel sequences, particularly of the years between the world wars, notably: Marcel Proust, À la recherche du temps perdu (1908–22) Georges Duhamel, Vie et aventures de Salavin (1920–32) and Chronique des Pasquier (1933–45) Roger Martin du Gard, The Thibaults (1922–40) Jules Romains, Les Hommes de bonne volonté (1932–47) Louis Aragon, Cycle du monde réel (1933–51) Jacques Chardonne, Les Destinées sentimentales (1934–36) The 19th-century predecessors may be distinguished as being rather "family sagas", as their stories are from the perspective of a single family, rather than society as a whole. Marcel Proust's À la recherche du temps perdu has come to be regarded as a definitive roman fleuve. Today, however, its seven volumes are generally considered to be a single novel. Proust's work was immensely influential, particularly on British novelists of the middle of the twentieth century who did not favour modernism. Some of those follow the example of Anthony Powell, a Proust disciple, but consciously adapting the technique to depict social change, rather than change in high society. This was a step beyond the realist novels of Arnold Bennett (the Clayhanger books) or John Galsworthy. Twentieth century The twenty-novel Aubrey-Maturin series by the English author Patrick O'Brian has been called