Goblin Slaves of the Central Massif

Recently, it has came to light in the hierarchy of the Frankish Noblity that some noble families within the Central Massif (and a few with holdings there), have took to capturing a number of goblins as slaves for mining. Most of the Frankish authorities initially took to massacres of Goblin tribes in the region to keep their numbers at manageable levels. Over the past few years a few families, namely the de Rais, the le Marchand, and de Sade families, have took to carrying out the massacres as an excuse to capture the fittest goblins for slave labour.
The reason for this is to force the goblins to work the mines under mercenary overseers. The goblins are worked to death and regular purges take place to remove the problem of uprisings. Absolutely vicious, the mercenaries take every opportunity to stamp their authority on the goblins, regularly killing one or two goblins on a daily basis, especially any that start to show a glimmer of leadership within the goblin ranks.
The goblins lot in these mines are short & backbreaking. Lifethreatining injuries are common, and any goblin that sufferes these are dragged to one side & left alone to heal or die. Help is minimal and only the goblin that can slip off to get help has any chance of survival. Even these that do, are usually singled out to be made examples of in front of the others. Slow & painful torture is used for these unfortunates.
At present, the numbers of goblins captured & enslaved for mining are starting to dwindle. Successive culls of the goblin tribes, and the amount dying in the mines are starting to exceed the birthrate, and the majority of Frankish nobles don't care. The latter view them as vermin that they can exploit for the foreseeable future.
In a few cases, the mines have suffered excessive damage and increased accidents. The goblins are blamed, but whispers are starting to leak out that the Knockers have noticed now the use of slave labour, and are taking offence at this practice as well as the deaths. A fwe believe that a few of the goblins are coming back in spirit form to cause the damage & accidents as a form of supernatural punishment for their treatment.

"I've heard of the practise but try getting into one of hose mines. I have trive and they're not officially marked down anywhere. Just a general idea of where they, and even if they are there at all. Might be able to pass the massacres off as keeping a problem at bay, but better a swift death than that treatment. The former at least gives the chance for the goblins to escape, and we get them later giving them an honourable death in combat. The latter, cruel, absolutely cruel.
As I say, its a cruel helpless practise. All because those families don't care."
Count de Ath speaking in Charlemagne's Court.