To be precise, Mace Windy was the Jedi Master who mentored the narrator of the unfinished 1973 Journal of the Whills fragment, the apprentice Chuiee Two (CJ) Thorpe.
In his 1983 book Skywalking, Dale Pollock (who got a lot of things in the early SW drafts extremely confused overall) mis-typed the character's name as "Mace Windu," and GL adopted this latter spelling for TPM.