I recently started trying out Legends Viewer, and it's pretty awesome, it's great for finding out about a specific nation's history. So I was looking through the time in which the world was generated, focusing on a specific Dwarven civilisation in a world that genned till 250. This civilisation expanded quite well and thrived, having about 11 forts at it's peak and won several wars.
Up until 249, when all but 3 forts become that sort of dulled colour they do in legends viewer when they are destroyed, followed a year later by complete disappearance or reclamation typically. In 250, they all disappear, as if destroyed. I was thinking that some other civilisation had steamrolled them, but I checked the individual histories of the sites and the only thing listed for the mysterious happening in 249 was 'Unknown' in the space that usually indicates when and how a site ended(In 19 XXX was founded by XXXX and it was destroyed by XXX in 156 or something like that). The unknown is something to do with the XML import being incomplete. I then noticed that this strange event had not just occurred to this specific Dwarven civilisation, but to all civilisations, though only Dwarven civilisations were affected as badly, most other races lost a couple of sites out of 20-100.
I'm going to check this out in in-game legends once my current adventurer kicks the bucket, but this seems to be strange and sort of explains why my Dwarven civs are always almost dead in all of my games. Has anyone else come across this? Is it a known bug or something?