A stand-alone AH novel written by S. M. Stirling, published in 2003.
Long story short, a giant meteor shower rains over the northern hemisphere of Earth during the 1870s, causing widespread destruction of habitable areas and the onset of global cooling. European, Russian and North American survivors (including the governments) are forced to evacuate and relocate to southern climes, mostly to their colonies (France to North Africa, Russians to central Asia, the British to India and Australia, etc.). Fast-forward more than a hundred years, to 2025, when the worst period of climate change has passed and the nations-in-exile are starting an effort to recolonize the lost ancestral lands. What unfolds is an adventure story deliberately patterned on the Victorian colonial adventure romances of the 19th century (with a few steampunkish trappings).
The novel has been generally received pretty well in the AH community and on AH.com. Many particularly liked its original PoD and the unique mixed countries-in-exile that developed from a mixing of colonial and European culture after the catastrophe. On the other hand, many have also criticized its setting for sacrificing a lot of believability in lieu of recreating a 19th century adventure novel atmosphere. These decisions included having clear-cut and often highly stereotypical good guys (British, Indians, French, etc.) and bad guys (Afrikaners, Russian villains), the southern portions of North America and Europe becoming depopulated and roamed by “cannibal tribes”, and technology remaining at a static, late 19th century level, despite the huge gap in time the exiled nations had at their disposal after the meteor catastrophe.
In addition to the novel, the same setting appears in the novella Shikari in Galveston (first published in the Worlds that Weren't anthology of AH prose).
For discussions about remakes/redux of the concept, please see the following section below.
In the past few years, several TLs and related projects centered on remaking or tweaking the premise of the novel have emerged on AH.com. They mostly focus on throwing out the more unrealistic stuff or stereotypical portrayal of some of the territories and nationalities and replacing them with more believable and/or accurate solutions.
Of particular note are the attempts to remake the North American parts of the setting, since many NA AH.commers have deemed the NA die-off as “too far-reaching, especially when the southernmost parts of the US are taken into account”. These related TL or backstory projects are usualy labled “Peshawar Lancers Redux”.