The Leatherbacks were a Freeguild gun company, from the Black Marsh Barony - part of the fenlands that stretched across the south of the Realm of Ghur. Many Azyrites considered them barbarians, with manners that put orruks to shame. They were commanded by Poppa Chown.
The warriors were all related, in ways too complex for an outsider to sort out and consequentially they had formed an intricate web of internecine alliances, blood feuds and grudges that had even duardin nodding in appreciation. 
Some were armed with Handguns, but others had to make do with a glaive or a halberd, until someone better equipped died and they could inherit his or her handgun. Duels could be fought over abandoned weapons, they were theoretically fought to first blood, but this usually wound up spurting from somewhere vital. 
On campaign they were noted as being able to endure the blistering days and freezing nights without complaint. Deadwalkers were not feared and in the Realm of Shyish were trapped, put into cages and used for target practice. 
| The Black Marsh Barony, scribe – good place. That’s where we’re from. A place for men. Not like this desert. Only bones in the desert. Sand gets everywhere. Scrape a man to his stilts.
~Poppa Chown .