The Novel of the Century: The Extraordinary Adventure of Les Misérables. By David Bellos. Particular Books; 307 pages; £20. To be published in America by Farrar, Straus & Giroux in March; $27.

“AS LONG as there are ignorance and poverty on Earth,” wrote Victor Hugo in his preface to “Les Misérables”, “books such as this one may not be useless.” Over the 155 years since it was first published in France and then elsewhere, the novel has never lost its relevance—or its popularity.

Around 65 film versions (the first in 1909) make “Les Misérables” the most frequently adapted novel of all time. The first stage musical opened in Philadelphia in January 1863. Since 1980 Alain Boublil and Claude-Michel Schönberg’s operatic melodrama has been performed more than 53,000 times in 44 countries and 349 cities. Yet, from the outset, adapters and translators cherry-picked elements from their supersized source. British admirers had to wait until 2008 for a complete English text of the novel in the order in which the author had planned it to be read. Even to lovers of “Les Mis”, Hugo’s world-shaking blockbuster can feel like a lost continent.

David Bellos, an English-born professor of French literature at Princeton University and an eminent translator, navigates through its five parts, 48 “books” and 365 chapters with clarity and wit. At once erudite and entertaining, he shows how the novel’s magic lies in its multitasking versatility. Hugo’s extraordinary feat is to deliver “an intricately realistic portrait” of France after Napoleon, “a dramatic page-turner” packed with suspense—and a demonstration of “generous moral principles” that readers still find appealing today.

Hugo, already the author of “Notre-Dame de Paris” and a literary superstar as a poet, playwright and novelist, began in 1845 to write his story of a former convict seeking a new life in a society rigged against the poor and outcast. Around the questing figure of Jean Valjean, freed from the prison-hulks in 1815 to make his way against the steepest odds, Hugo stitched a vast but “very tightly knit” tapestry of social strife and personal rebirth.

The revolution of 1848, in which the radical firebrand discovered that “his head was with order” although his heart “was with the poor”, interrupted Hugo’s mammoth project. It resumed after the exiled writer, banished by the upstart emperor, Napoleon III, settled on the Channel Island of Guernsey: no longer a “brilliant careerist” but a “stand-alone protester”.

Curiously, this “tiny feudal outpost of the British crown” hosted the gestation and birth of a book that won hearts and changed minds across the world. The editing and printing of the precious manuscript depended on the schedules of Queen Victoria’s Royal Mail and the Guernsey steamer timetables. In 1861 “the biggest deal in book history” saw Hugo paid the equivalent of 20 years of a bishop’s stipend: enough “to build a small railway”. By late 1862, the year of publication, Charles Wilbour’s English translation was reported to be “the largest order ever placed for a book in America”.

Save for Hugo’s literary rivals (Alexandre Dumas likened it to “wading through mud”), everybody loved the long haul of Valjean’s rehabilitation in the company of characters who soon entered folklore: the street-girl Fantine, her daughter Cosette, the urchin Gavroche, the student Marius. Shorn of its condemnation of slavery, the novel even circulated in a pirate edition among Confederate soldiers during the American civil war. In a weary pun on their commander’s name, they dubbed themselves “Lee’s Miserables”.

From the humane treatment of ex-offenders to the care of street children, “Les Misérables” spearheaded calls for reform and contributed to “the future improvement of society”. Few books really change the world. This one did, long before it broke box-office records on stage. In the musical Hugo’s hero intones—in a song loved by television talent-show contestants—“Bring Him Home”. Mr Bellos does just that, as he restores “Les Mis” to its maker and his times.