single word requests - What is the name of someone who was something before you?

I've completely forgotten the word you say when someone had your job or something before you, and then you took over.

I'm trying to write a History Essay and my sentence is

The legacy of German's defeat in World War One hung in the air for years after Hitler's ______'s signed the Treaty Of Versailles

I keep thinking its something like oppressor or something but I'm stuck.