United Kingdom

15th (The King's) Hussars

Cabinet Card Dublin studio 

15th Hussars Sergeant

He's proudly displaying his regimental crest as a "Sergeant's arm badge" on his right sleeve. 

Note that the tunic is fastened in the officer pattern with olives instead of button balls. His pillbox hat is also particularly embroidered - this pattern is specific to the 15th Hussars and called the "Austrian wave".

The 15th was stationned in Ireland from 1889 to 1895 before being shifted to Aldershot.