Abstract : On 6 June 1944, American and British forces stormed across the Normandy beaches to begin Operation Overlord, the far-reaching campaign for the liberation of Europe. The unqualified success of that bold venture, which led to the defeat of Nazi Germany, stressed the importance of a well-designed and well-executed campaign as an adjunct to operational warfare. Yet, shortly after the Second World War, this notion of warfare with its associated campaigns largely disappeared from contemporary military thinking. More recently, however, a resurgent interest in operational warfare as an essential step in achieving overall victory in war has evolved among military leaders. Unfortunately, somewhat less attention has been placed on its indivisible component -- the campaign. To better convey the notion of campaigning, this essay delves into a series of campaign fundamentals from four points of view. First, numerous campaigns of the Second World War, in Europe, the Pacific, and Africa, illustrate the elements of war that must be amalgamated to produce victory. Although Overlord was but one of these memorable campaigns, a brief review of its salient points provides a useful historical perspective of a campaign. Second, a precise definition of operational warfare and its companion, the campaign, serves to simplify many of the complexities inherent in these terms. Third, a comparison of campaign planning with other planning functions further delineates the unique wartime role of the campaign. Finally, by examining some of the campaign's major components -- the mission, the concept of operations, and the logistics concept -- we will see these disparate components quickly coalesce under the unifying rubric of the campaign.