Far More Dangerous
DM Note: I have not created all the Great Houses to leave room to add some in play, especially if the PCs want to create a new House either as a rival or to belong to.
The Great Houses of Darven have their fingers somewhere in almost all of the trade in the world. They each own fleets of merchant ships, caravans of wagons, and armies to protect them. That being said, the Houses have varying degress of interest in any good that needs to be produced or moved. There are even rumors that though drugs, poisons, and slavery are illegal in Darven itself, some Houses dabble in those markets anyway.