On the death of a master within the Hegemony of the Three Ethshars their last apprentice automatically inherits all the tools of the trade, whether that’s a carpenter’s tools or a wizard’s ingredients or whatever. The master’s family inherits everything other than tools of the trade. If the family is left poverty-stricken, it’s the former apprentice’s responsibility to ensure they don’t starve.
It’s the last apprentice because it’s assumed that all earlier apprentices are already established in their trade now, or he wouldn’t have taken on another one.
If the former apprentice is a master himself, then he’s expected (but not required) to pass the inheritance on to someone else, either the family or his own apprentices.
If there are no apprentices — which was Nabal’s situation; he was eccentric, as living where he did demonstrates — then the family inherits.
This isn't necessarily tied to the Great War. There might be a connection, but it is not clearly defined.