The purpose of this study was to trace the historical development of the Order of Aaron, or Aaronic Order, the governing body of the True Church of God, and to determine its present status in the religions of the world. The study included a summary of the origin of the Order, historical development, present establishment, organization within the Order, including types of memberships, as well as a resume of the theological teachings and practices of this group.Research involved a study of the publications of the Aaronic Order. Information from these sources was supplemented by correspondence and personal interviews with members of the Order of Aaron, namely the Chief High Priest, Dr. Maurice Lerrie Glendenning, and his wife, Dr. Helen R. Glendenning; Robert J. Conrad, First High Priest; and Bliss G. Childs, Second High Priest.The result of this study indicates that all material presented herein is the belief of the leaders of the Aaronic Order and it is printed with their approval as being true and an accurate summary of their history and doctrinal development.