This article details--no, it doesn't summarize well. Here's an entrée:

"Out of this group would arise several radical separatist movements with overlapping membership, including a religious one called Lux Madriana—worshiping a female god with rituals supposedly passed down from a “magical matriarchal community” in a distant past—and an elaborately fleshed-out otherworld called Aristasia. Much like the rich fantasy worlds created by Tolkien or the Brontë sisters, Aristasia became an ever-growing obsession for its creators, with its own customs, calendar, literature, and history, to the extent that some of the worldbuilders eventually dropped out of university to attend their own unofficial Aristasian school instead. In Aristasia there were two genders, both female (assertive brunettes and demure blondes); the decadent modern world was known as The Pit; and the word for person was not man but maid."

ht Emily Short

FURTHER: A short, somewhat melancholy history of Aristasia-in-Telluria