And you thought Louis Menand’s “The Free World” was long! Simon Heffer’s “The Age of Decadence: A History of Britain, 1880-1914” clocks in at 897 printed pages with narrow margins. It’s a book that will see a reader through May and, quite possibly, June and July as well.

Uh, you say, why exactly would anyone care to read almost 900 pages about politics, art, music, fashion, journalism, architecture, education, drama, censorship, war, sex, scandal, social unrest, insider trading, rioting and much else in late Victorian and Edwardian England? Simple: What Heffer recounts is fascinating in itself, but also eerily familiar, almost contemporary. History, after all, provides perspective on the present.

It was, writes Heffer — a longtime journalist who now teaches at the University of Buckingham — an age of swagger, one obsessed with show and display. There was “an undue concentration of wealth among a privileged few,” but also an underclass that was gradually learning to organize, march and protest generations of abuse and exploitation. John Burns, a leading voice in the labor movement, denounced the House of Commons as composed of capitalists “no more likely to legislate in the interests of the working men than were the wolves to labour for the lambs.” To hang them, he hyperbolically declared, “would be to waste good rope.”

The condition of women was abominable. In protest, a group of female workers from a match factory, who had been docked a shilling of their meager wages to fund an unwanted monument honoring Prime Minister William Gladstone, “surrounded the statue and cut their arms and let them bleed over it.” No matter how exceptional a woman’s intellectual gifts, her opportunities remained severely limited: “Philippa Fawcett, from Clapham High School, recorded in 1890 the highest marks of any candidate in the Cambridge Mathematical Tripos.” She still wasn’t allowed to enroll at the university.

When not being worked to death in mills or domestic service, many women were sexually exploited because of their poverty and desperation. Young girls could actually be bought as sex slaves. To shine a light on this outrage, muckraking newspaperman W.T. Stead paid five pounds for a 13-year-old girl and then produced a sensational four-part exposé of juvenile prostitution in London. The Pall Mall Gazette carried a headline any tabloid would covet: “The Maiden Tribute of Modern Babylon.”

Meanwhile, Queen Victoria’s son, the future Edward VII, devoted his energies to gambling, overeating, pursuing women and roistering with unsavory companions. One of the most unsavory, Sir Charles Dilke, made his brother’s mother-in-law his mistress, then seduced her 19-year-old daughter. Edward nevertheless kept him on as a crony and adviser.

It was an age of empire builders, whether in government or business, but also one of rebels against society’s constraints and prejudices. The music hall legend Marie Lloyd never sang any overtly dirty lyrics, but knew how to employ winks and gestures to lend innuendo to the words of “She’d Never Had Her Ticket Punched Before.” Convicted of “gross indecency,” Oscar Wilde would suffer two years in prison, emerging as the iconic martyr of gay liberation. When Emmeline Pankhurst inaugurated the campaign to gain “Votes for Women,” she used one of her arrests to accuse the entire male legal profession of moral turpitude, pointing out that a recent case “had to be retried because the judge who originally presided over it had been found dead in a brothel.” The judge in her own trial was outraged at this, “not least because the story was true.”

In prison, the suffragists regularly embarked on hunger strikes, some being brutally force-fed with tubes through their mouths or even their nostrils. After one such horrendous ordeal, its unwilling victim still managed to croak “No surrender.” Continually ignored or mocked, the women’s movement grew increasingly violent. Mary Richardson slashed the National Gallery’s recently acquired Velazquez painting — the nude Rokeby Venus — while shouting, “You can get another picture, but you cannot get a life, as they are killing Mrs. Pankhurst.” Highborn ladies would stash hammers in their handbags and bring them out to smash windows and storefronts. Emily Davison threw herself under the hoofs of the king’s racehorse, succumbing to her injuries four days later. During that time, she received a letter that began “I am glad to hear you are in hospital. I hope you suffer torture until you die.” Trolls spewed their vile even then.

These indomitable feminists refused to conform to the image of a woman as meek and docile, the so-called “angel in the house.” They simply wouldn’t back down. As Heffer writes, “It slowly dawned on the anti-suffrage movement that it might have underestimated the commitment of its opponents.” Replace “anti-suffrage movement” with “adversaries of Black Lives Matter” and you could be summing up last year.

Other chapters of “The Age of Decadence” address the era’s widespread fixation on eugenics, its crisis of religious faith, the poetry of Thomas Hardy, A.E. Housman and Rupert Brooke, the stirringly patriotic music of Elgar and Vaughan Williams, the doomed Scott Antarctic expedition, the cult of Nature and, not least, Robert Baden-Powell’s creation of the Boy Scouts.

In short, Heffer’s book offers a glorious, if somewhat relentless abundance. Did you know that Henry James gave away the bride at Rudyard Kipling’s wedding? That Archduke Franz Ferdinand — he whose assassination would ignite World War I — sat next to Queen Victoria at her Diamond Jubilee banquet? Or that the queen died in the arms of her grandson, Kaiser Wilhelm of Germany?

Still, my favorite factoid in a book packed with them might be this one: Edward Stanley Gibbons, Britain’s leading authority on stamp collecting — the hobby grew wildly popular in this period — “had five wives, four of whom predeceased him at early ages. There has been speculation their ends were not always from natural causes, but encouraged by his early training as a pharmacist.” Clearly, “The Age of Decadence” could also be, for good or ill, an age of individual initiative.

Michael Dirda reviews books for Style every Thursday.

The Age of Decadence: A History of Britain: 1880-1914

By Simon Heffer

Pegasus. 897 pp. $39.95