Determining an age for strata that contain ancient bones or stone tools requires the combined techniques of stratigraphy, lithologic correlation, radiometric dating (e.g. 40Ar/39Ar), and magnetic polarity zonation. By the early 1960’s, the combined application of K/Ar (a precursor to 40Ar/39Ar) and magnetostratigraphy generated the first accurate dating of bones and stone tools in Olduvai Gorge, Tanzania. These results doubled the age of ‘Early Man’. Research continues to fill in the details of our expanding unwritten past with a broad array of hominins found in diverse places across Africa and Eurasia. This talk will summarize current research findings with an emphasis the use and methods of magnetostratigraphy.