Originally posted by grinsekeatzchen:

Dont you get raids when you kill a certain boss? Nothing to do with the trophies?

Killing the bosses doesn't matter. The base attack events don't progress until you actually hang their trophies. This affects all players on the server, so a brand new player starting out on an older server is going to have a really rough time evading all of the greydwarf brutes and shamans and everything else that comes out at night.