Fans of Terry Pratchett wear a lilac on 25 May in remembrance of the Glorious Revolution of Treacle Mine Road which took place during the novel Night Watch. Following Pratchett’s diagnosis of early onset Alzheimer’s in 2007, fans also Wear the Lilac in celebration of Pratchett and to raise awareness and funding for Alzheimer’s research.
The Revolution of Treacle Mine Road ended the increasingly tough reign of Lord Winder. Tension had been rising, and while the nobility arranged a quiet succession by Lord Snapcase in the background, the people on the streets started a revolution and attacked Watch Houses all over the city. A few streets around Treacle Mine Road were barricaded at first. Soon more people started barricading streets, barricades were moved forward and merged together, covering at least a quarter of the city – including the food industry. The resulting area was called The People’s Republic of Treacle Mine Road. The watchmen of the Treacle Mine Road Watch House led the Republic together with some enthusiastic angry young men, among them the then-living Reg Shoe.
A change in history resulted in Sam Vimes under the name of John Keel saving the Republic until Lord Snapcase became Patrician. Unfortunately Many people died, after an attack planned by Carcer prompted by Snapcase’s concerns about what “Keel” could get up to if left alone for a month after serving as such a prominent leader after less than a week in the city. Each year, on the 25th of May, a group of survivors of the uprising gathers at Small Gods’ Cemetery to honor the casualties with lilacs and, affectionately, one hard-boiled egg (from Madam Roberta Meserole). The seven killed were mostly Watchmen from Treacle Mine Road : John Keel, Cecil Clapman, Horace Nancyball, Billy Wiglet, Dai Dickins, Ned Coates, and, temporarily, Reg Shoe. The 25th of May is also memorialized, among those who survive, by the wearing of lilac on that date. Persons known to wear it include Sam Vimes, Fred Colon, Nobby Nobbs, Cut-Me-Own-Throat Dibbler, and, improbably, Havelock Vetinari (he, at the time a young assassin, has kept his and his aristocratic aunt Lady Roberta Meserole’s, involvement secret.