antecedents
/ˌantɪˈsiːd(ə)nt/
noun
A thing that existed before or logically precedes another.
some antecedents to the African novel might exist in Africa’s oral traditions
precursor,forerunner,predecessor
adjective
Preceding in time or order; previous or pre-existing.
antecedent events
previous,earlier,prior,foregoing,preceding,precursory