Raid caravan is a quest given by a lord of a friendly faction. A lord is unhappy with the peace between his faction and another faction it is not currently at war with and wants you to provoke them by attacking their caravans and leaving behind evidence to lead them back to the quest giver's faction. The lord claims that he cannot do this himself as rival lords are already looking for an excuse to oppose him, but reasons that you would be able to get away with it. This quest takes 100 days before it will be available again.