Cultural event
For a large time Ûnduleah was a mostly cold and barren land. Only small populations of dwarfs lived in clans far apart along the volcanic ridges. The majority lived on Aachor and along the Kiridûn mountains The clans were run by dwarf chiefs, with up to 50 dwarfs in their clan. To share resources, knowledge and skills (and genes), some small dwarf clans exchanged a small group of chosen ones with other clans every few decades.
After the Dwelling Days, when the dwarves emerged again from the Kiridun mountains, the world was cold, but liveable. The dwarves explored and expanded slowly throughout Dûnn and Unem, and eventually in Aachor. The winters however got colder every year, until finally the winter months were too cold to survive anywhere without a non stop heat supply. Forests could not keep up with this heating demand, so eventually the dwarves settled near lava rifts. This forced relocation cut off many dwarven clans from each other and they became somewhat isolated. In the time before the Silver Rain Ûnduleah was a mostly frozen land. With many glaciers, tundra steppes and ice caps. The South Sea was the only sea that stayed ice-free year-round. The summers were short and mild and the winters were long and harsh. The world could only sustain a small number of dwarfs since their main food source came from fishing, hunting and gathering the few winter-hardy animals and plants. The clans were run by dwarf chiefs, with up to 50 dwarfs in their clan. To share essential resources, knowledge and skills, a small envoy of dwarves travelled to the nearest clans in the summer following the eruption of the Barkaru volcano (every 20-40 years or so). Each clan sent and received a small envoy of new people, creating a culture where sharing and cooperation became very important.