Old province of birth (5)
I believe the answer is:
natal
I believe this clue is a double definition.
'old province' is the first definition.
(former South African province)
'of birth' is the second definition.
(I've seen this in another clue)
(Other definitions for natal that I've seen before include "Concerned with the birth" , "former SA province" , "Of or from one's birth - in S African province" , "Like a seat" , "Province of South Africa" .)