Atahualpa's subjects (5)
I believe the answer is:
incas
'atahualpa's subjects' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for incas that I've seen before include "People from Andes who settled in Peru" , "Old Peruvians" , "Ancient Peruvians" , "Members of ancient Peruvian race" , "People of ancient Peru" .)