pinanigrans is one of the oldest conventa in Britannia, founded in the ninth century. The conventum Tremeris occupies a complex of caverns under the Black Mountains of southern Wales, with an entrance at the rear of a large cave.

Spinanigrans dominated Hermetic politics in Britannia since the Schism War, but concerted maneuvering by Voluntas has eroded that dominance over the past several decades. It remains a powerful conventum, however, home to two Tremeris Archimagi and the Quaesitor Praesidens Britanniae, who is also an Archimagus.