My grandfather had the pre-1962 GSM earned in 'Iraq' in 1920.
Not sure when it was first issued but 40 odd years for each is something.
First issued in 1918, with the clasp for South Persia, last one was Brunei in 1962. Only issued to the Army and RAF - the Navy had their own medal until the 1962 GSM came in, which was tri-service.