Simplify the following text for a Grade 7 native English-speaking person.
Original: As an official in post-independence 1960s Cameroon , Biya rose to prominence under President Ahmadou Ahidjo .
Simplified: After graduating , Biya returned to Cameroon and worked in the government . In 1975 , the President Ahmadou Ahidjo gave the job of Prime Minister to Biya .