In the case of State, Scholars have demontrasted that senior officials' ability to embody general interest is the result of long-term social processes marked by the concomitant construction of the State and civil servants as a social group. Though the European civil servants' situation is different from that of State civil servants, their ability to maintain their central role and defend the European interest invites us to turn our enquiry to processes that realize them (in the double sens of Berger and Luckman) as a group whose objectivation is both strong and rooted into European institutional “realities”. It is one of the aspects of this process that we would like to analyse by focusing on the unions of European civil servants. By examining the social process of crossed unification between the cause, the interest, and the group led by European civil servants unions, this sociological based approached would like to clarify the relation which unites the eurocrats body with the UE institutions.