El poder en Moncloa: el jefe de Gabinete del presidente del Gobierno

This article presents an original research based on a set of interviews that includes both almost all the chiefs of staff of the office of the President of Government and one of the previous presidents of the Spanish Government. It tries to understand, from this double point of view, the two vertexes of the relationship between the prime minister and his main adviser. The study deals with the profile, the emergence and expansion of this political figure and its evolution, with unpublished documents from Moncloa archives. It also shows the double power of exclusion and connection the chief of office has accumulated and it develops a comparative analysis of the power exercised by the various occupants of the post since the transition to democracy.