[1] He has become famous for his posthumously recovered 15,145-page manuscript for a fantasy novel titled In the Realms of the Unreal, along with several hundred drawings and watercolor illustrations for the story[2] and two further works of literature.

When he was four years old, his mother died of puerperal fever after giving birth to a daughter, who was given up for adoption; Darger never knew his sister.

The Lincoln asylum's practices included forced child labor and severe punishments, which Darger would later seemingly incorporate into his writing.

With the help of his godmother, Darger found menial employment in a Catholic hospital and in this fashion continued to support himself until his retirement in 1963.

He collected found objects from the streets – including shoes, eyeglasses, and balls of string – to exhibit alongside artwork in his home-studio.

[4]: 137–149 In 1930, Darger settled into a second-floor room on Chicago's North Side at 851 West Webster Avenue in the Lincoln Park section of the city, near the DePaul University campus.

It was in this room for the next 43 years that Darger would imagine and write his massive tomes (in addition to a 10-year daily weather journal and assorted diaries) and collect and display artwork[9] until his death at St. Augustine's Home for the Aged (the same institution at which his father had died) on April 13, 1973, one day after his 81st birthday.

[10] In the Realms of the Unreal is a 15,145-page work bound in fifteen immense, densely typed volumes (with three of them consisting of several hundred illustrations, scroll-like watercolor paintings on paper derived from magazines and coloring books) created over six decades.

[3]: 64 The largest part of the book, The Story of the Vivian Girls, in What is Known as the Realms of the Unreal, of the Glandeco-Angelinian War Storm Caused by the Child Slave Rebellion, follows the adventures of the daughters of Robert Vivian, seven princesses of the Christian nation of Abbieannia who assist a daring rebellion against the child slavery imposed by John Manley and the Glandelinians.

The elaborate mythology includes the setting of a large planet, around which Earth orbits as a moon (where most people are Christian and mostly Catholic), and a species called the "Blengigomeneans" (or Blengins for short), gigantic winged beings with curved horns who occasionally take human or part-human form, even disguising themselves as children.

Images of children often served as his inspiration, particularly a portrait from the Chicago Daily News from May 9, 1911: a five-year-old murder victim, named Elsie Paroubek.

Paroubek's disappearance and murder, her funeral, and the subsequent investigation, were the subjects of a huge amount of coverage in the Daily News and other papers at the time.

Through their sufferings, valiant deeds and exemplary holiness, the Vivian Girls are hoped to be able to help bring about a triumph of Christianity.

Darger provided two endings to the story, one in which the Vivian Girls and Christianity are triumphant and another in which they are defeated and the godless Glandelinians reign.

The images of daring escapes, mighty battles, and painful torture are reminiscent not only of contemporaneous epic films such as The Birth of a Nation (which Darger might easily have seen)[15][16] but of events in Catholic history; the text makes it clear that the child victims are heroic martyrs like the early saints.

Art critic Michael Moon explains Darger's images of tortured children in terms of popular Catholic culture and iconography.

These included martyr pageants and Catholic comic books with detailed, often gory tales of innocent female victims.

Written after The Realms, it takes that epic's major characters—the seven Vivian sisters and their companion/secret brother, Penrod—and places them in Chicago, with the action unfolding during the same years as that of the earlier book.

The girls go about exorcising the place, but have to resort to arranging for a full-scale Holy Mass to be held in each room before the house is clean.

Nathan Lerner, an accomplished photographer whose long career, The New York Times wrote, "was inextricably bound up in the history of visual culture in Chicago,"[19] immediately recognized the artistic merit of Darger's work.

At the Outsider Art Fair, held every January in New York City, and at auction, his work is among the highest-priced of any self-taught artist.

1, New York, 2000), where it was presented alongside prints from the famous Francisco Goya series The Disasters of War and works derived from these by the British contemporary-art duo Jake and Dinos Chapman.