The origins of a number of important public enterprises can be traced to the First World War. This article deals with the Commonwealth Line and traces the factors which led to its creation by government and those that caused its privatization. The article traces the history of the Commonwealth Line from its formation as a desperate measure to overcome a wartime shipping shortage that was preventing the transportation of vital primary products, especially wheat. Emphasis is placed on bargaining between the Australian and British governments over the tonnage to be allocated to Australia. At the end of the war the Line’s obsolescent ships and its need for greater public investment was not welcomed by the Commonwealth government. The article concludes with a discussion of the decline of the Commonwealth Line after 1918 and emphasizes the role of the British shipping cartel and labor costs in its demise.