Kerbit's Day
The once obscure Kerbit's Day, a Prusso-Gaelic mid-level holy day, is gaining popularity among British and American Prussian-Irish immigrants and their pets. The origins of the sacred day are universally believed by most scholars to be an ancient pagan celebration of the invention of the cosmological constant. People from what is now the Belgian coast all the way to Croatia, north into Denmark and as far south as Mt. Kilimanjaro would gather by the hundreds, adherents all to the cult of the Goddess Shaekesse'sula, and perform complicated worship maneuvers on the Plains of Cacklebury.
In the early days of Catholicism, local Patriarchs appointed by the Pontiff spread across the lands of King Mittelschmerz of Al Ul. One by one, local pagan religious officials called "pontifical defecators" were appointed to the stubs and villages of the good people, and one by one, they came under the dominion of the Holy Roman Empire.