These four novels remain must-reads 100 years after they were published. They not only shaped the literature of the 20th century, but they altered our views of life and reality—and what can and cannot be written about.

When people talk about the Great American Novel, The Great Gatsby often comes to mind. F. Scott Fitzgerald’s classic brings us back to the Jazz Age of the 1920s, which combined wealth, frivolity, and happiness wrung from pleasure and self-indulgence. Gatsby, the enigmatic hero, is incredibly rich yet pines away for the one thing he cannot have: the love of the frivolous Daisy Buchanan.

In 1928—only 10 years after the end of World War I—Erich Maria Remarque’s classic war novel All Quiet on the Western Front was published in Germany. The book, which went on to sell millions of copies in over 22 languages, centers on the experience of young Paul Baümer, who is coaxed into joining the German army. We follow him as the years of the war wear on—with horror, tragedy, and boredom, sprinkled with brief moments of enjoyment.

Ernest Hemingway’s A Farewell to Arms has been called the premier American novel of World War I. It also focuses on the experiences of one participant: Frederic Henry, an American who volunteers for the Italian ambulance corps. Although he behaves heroically, the novel tells of his progressive disillusionment. Convalescing after a wound, he meets the English nurse Catherine Barkley. Their haunting and tragic love story takes place as Frederic deserts from the Italian army, taking Catherine with him to Switzerland.

The Sound and the Fury, first published in 1928, focuses on the haunted Compson family, faded Southern aristocrats who fall into financial ruin, lose their dignity, and end in tragedy. The novel remains bold and experimental in its narrative, combining the perspectives of various characters, including the mentally retarded Benjy; Quentin, a suicidal Harvard graduate; and Dilsey, a black family servant. The stream of consciousness narrative reflects the progressive dissolution of the Compson family.

These novels—all written a century ago—remain gripping and unforgettable.