Anywhere form the mid 19th century prior to WWI. I am having some trouble in finding books on the state of the combatants returning from these conflicts aside from small snippets of newspapers taken form around the time.
Any help would be greatly appreciated.
EDIT: Combatants from who fought for the opposing side during this time period would also be appreciated.
I'm not sure what information you are looking for but you might try
The VETERANS, A history of the Enrolled Pensioner Force in Western Australia, 1850-1880 by F.H. Broomhall, published 1989 Hesperian Press, Western Australia
The enrolled pensioner force was recruited in Britain from qualified veterans (to be pensioners they had either served 20 years or had been discharged honourably at less than 20 years for medical reasons) of the British Army.
They initially served as guards on convict ships going out to Western Australia, and on arrival formed a militia on the promise of land grants.
The book lists them in some detail and although it doesn't say much about their previous service, it does provide enough detail that you can obtain their British Army service records, which in some cases also contain information about their later lives if it effected their ongoing pension entitlements.