This article summarises the theses of a five-volume work which the author has been publishing in Spain since 2006. The last volume, dealing with the collapse of the resistance to Franco by the Spanish Republic, was co-authored with Fernando Hernandez Sanchez. Three perspectives have been applied: firstly, the war policies of the Spanish Republic. The main points of Franco´s politico-military strategy are also included since he was interested in lengthening the war. Secondly, the hotly debated issue of the political, diplomatic and material support received by both sides. Finally, the reactions of the great European powers (England, France, Germany, Italy, and the USSR) to the events in Spain. The main emphasis is on the USSR. These perspectives are applied at two levels. The first level is narrative and analytical. The second contains a critical discussion of the theses defended by the most relevant authors who have dealt with the subjects of the first level. Two of the five volumes contain a large amount of primary relevant documentary material in two CDs. Another two volumes contain documentary appendices. All five volumes are based on the research carried out by the author(s) in some forty official and private archives both in Spain and abroad.