Glorious Twenty-Fifth of May Date in the current year: May 25, 2025

The Glorious Twenty-Fifth of May is a commemoration of the People’s Revolution of the Glorious Twenty-Fifth of May, as depicted in the Discworld novel Night Watch. The fall of Lord Winder’s increasingly oppressive rule marked a turning point in the history of Ankh-Morpork. While the nobility quietly arranged for Lord Snapcase to succeed him, unrest boiled over in the streets. The citizens launched a revolution, targeting Watch Houses throughout the city.

At first, only a few streets near Treacle Mine Road were barricaded. But the movement quickly grew: barricades multiplied, merged, and expanded until they covered nearly a quarter of the city, including its food supply. This area became known as the People’s Republic of Treacle Mine Road. Leadership of the Republic fell to the guards of the Treacle Mine Road Watch House, along with a group of passionate young revolutionaries.

Though the Republic was originally overrun, the events of Night Watch resulted in Sam Vimes (impersonating John Keel) holding the Republic together until Lord Snapcase officially took power. Despite the changes to the timeline, those who died in the original uprising still perished in an attack orchestrated by Carcer, acting on Snapcase’s paranoia about what “Keel” might do if given more time to influence the city.

Seven people died in the uprising, most of them from the Treacle Mine Road Watch House: John Keel, Cecil Clapman, Horace Nancyball, Billy Wiglet, Dai Dickins, Ned Coates, and, sort of, Reg Shoe, who became a zombie. Every year on May 25, a group of survivors of the revolution gather at the Little Gods’ Cemetery to remember the fallen. They lay down lilacs and a hard-boiled egg, a token from Madame Roberta Meserole.

Those who survived also commemorate the day by wearing lilac on May 25. Known wearers include Sam Vimes, Fred Colon, Nobby Nobbs, Cut-Me-Own-Throat Dibbler, and, surprisingly, Havelock Vetinari, who as a young assassin played a hidden role in the events alongside his aunt, Lady Roberta Meserole. Their involvement remains a closely guarded secret.

The fictional celebration was adopted by fans of Terry Pratchett’s works, who began wearing lilac sprigs on May 25 to commemorate his writing. In 2007, Pratchett announced that he was suffering from Alzheimer’s disease. His fans started the Match It For Pratchett campaign to raise awareness of Alzheimer’s. Fans are encouraged to wear lilac in support of Pratchett and donate to Alzheimer’s research funds.

But why May 25? Terry Pratchett’s choice of date seemed arbitrary until his longtime business manager Rob Wilkins revealed on Twitter in 2020 that Pratchett had asked him to find “a day in the year that would cause the least offense”, and Wilkins settled on May 25, the birthday of English singer-songwriter and musician Paul Weller.

The Glorious Twenty-Fifth of May coincides with two other fan holidays: Geek Pride Day and Towel Day. Sometimes fans of Terry Pratchett and Douglas Adams celebrate the day together and call it Wear a Lilac Towel Day.