Welcome to the forum. I do hope that you are able to find out more about George George here. Do you happen to have his South Africa Medal?
George George was definitely with the 90th Regiment in the Zulu War. As Gary stated he is confirmed on the Forsyth Medal Roll as a Sergeant. 108, George, G., clasp “1879”. The Medal Roll at the National Archives, WO 100/47 lists him as Private, 108 George, G., and showing he was a Sergeant at the time of earning the medal.
The 90th was present at the battle at Kambula (March 29, 1879) and again at the battle of Ulundi (July 4, 1879) where G. George was “slightly wounded.” His name appeared on the official list of killed and wounded of General Wood’s Flying Column as “No, 1,118, Sergeant G. George, 90th Light Infantry.”
I checked Rai’s lead from the “British Army Worldwide Index for 1871” which has two listing for G. George. One is for “George George, 1118, Corporal, 90th (Perthshire Light Infantry) Regiment of Foot.” The second is for “George George, 1118, Sergeant, 90th (Perthshire Light Infantry) Regiment of Foot.” This seems to suggest that he received his promotion to Sergeant that year. I know little about Army service numbering system from the late 1880s, but it appears that G. George received a different number when he became a non-commissioned officer. Someone more knowledgeable may explain the 2 different numbers.
As for the reason why he is on the medal roll at the Archives as “private” instead of “sergeant” is because on the 27th of October, 1879 G. George was tried by Court-Martial at Pinetown, Natal for the charge of “Absence” and was sentenced to a “reduction” in rank to private. The sentence was later “remitted.”
If you would like to read about the 90th in the Zulu War here are a couple of books to start with.
“Blood on Painted Mountain” by Ron Lock” and “Records of the 90th Regiment (Perthshire Light Infantry)” (pages 222 – 260) which is online at:
Hopefully, this will give you a start in you search for more information about you ancestor.