Historical events are identified which led to the development of combines with rotary threshing and separation. Efforts by inventors, engineers and researchers were reviewed to determine their contribution to the introduction of rotary concepts in combine harvester threshers. World events, changes in agricultural production practices and business decisions have all influenced advancement of rotary harvesting technology. Bringing resources together for successful development of the first complete line of Axial Flow Combines was a major accomplishment. Recently introduced improvements for these Axial Flow Combines are reviewed.