[Velusion]

In a province?

It's actually not that hard for a large enough force to pillage a province to a point that the population reaches zero. Once it is zero, it never grows back. I've done it many times as LA Ermor in another MP game. In that game it took me about two turns to completely liquidate the population of a medium sized province with a very large undead army.

The province will always have a minimum supply of 10 and the resources (if I remember correctly) also get reduced to almost nothing.