General staff ultimately administered business (6)
I believe the answer is:
franco
'general' is the definition.
(General Franco of Spain)
'staff ultimately administered business' is the wordplay.
'ultimately' indicates one should take the final letters.
'administered' becomes 'ran' (run can mean to administer or control).
'business' becomes 'co' (short for company).
The last letter of 'staff' is 'f'.
'f'+'ran'+'co'='FRANCO'
(Other definitions for franco that I've seen before include "Last dictator of Spain" , "was head of state" , "General . . . . . . was Spain's last dictator" , "Former Spanish dictator" , "Spanish general and dictator" .)