unusual glass negatives of hanged men

Recently purchased these unusual glass negatives at auction.
The owner didn't leave any provenance, so I don't know what country these are from.

Each of the three negatives show soldiers, military men or possibly militia with men who've
been the victim of hanging and all are in fact dead.

Please tell me what country these are from, what Era (or war) and - if you know - why these men have
been killed?

Thanks!!!

Nessa