predecessor
noun [ C ]
uk/ˈpriːdɪˌsesər/ us/ˈpredəsesər/the person who had a particular job or position before someone else:
His predecessor had left him with many problems to address in the department.
a machine, system, law, etc. that has been replaced by a new one:
The new model retains all the advantages of its predecessor but offers five times the speed.