Interregnum

The Interregnum is the historical period between the collapse of the Federal Empire and the resumption of starflight between worlds. By its very nature, the Interregnum is difficult to date precisely. Some worlds experienced the collapse early, some late; some lost starflight for five years, some for fifty, some for five hundred; some-like Avalon, Baldur, Newholme, and Old Earth-were never really isolated from the rest of humanity, while others perhaps have still not been rediscovered. It is commonly said that the Interregnum lasted a "generation"; this is workable enough as a rough approximation, if only the major human worlds are considered.

"Thousand World" stories which take place during the Interregnum include:
 * Bitterblooms
 * In the House of the Worm

Partial Timeline (ai-1+)

 * The Federal Empire ceases to exist as a political entity
 * Old Earth and other powerful human worlds isolate themselves, and commercial starflight effectively ends for a generation
 * The Hrangan Empire is dismembered by its former slaveraces and by human colonials
 * The aftereffects of the Hrangan biowar plunge some worlds into ecological disaster, while other worlds devolve into near-savagery or develop variant cultures
 * Avalon deploys 6 survey ships into the galaxy to understand the effects of the Interregnum; 3 of the ships return with information on the closest star systems and the Avalonians re-initiate starflight on a limited local basis
 * One of Avalon's survey ships, commanded by the cyborg Kleronomas, does not return immediately and instead extends its voyage for decades, surveying hundreds of isolated planets
 * Letheland is rediscovered
 * ai-Emeral is colonised from Daronne (the acronym for "After Interregnum" forms part of the planet's name)
 * Kleronomas returns to Avalon and establishes the Academy of Human Knowledge
 * Newholme proclaims itself the “Union of Humanity” but this title is only acknowledged by three neighbouring worlds