The movement widely known as the European marches against unemployment, job insecurity and social exclusion—first demonstrated its mobilization capacity in Amsterdam on June 14, 1997, when almost 50,000 people turned out against the holding of the European Summit. What made the event even more remarkable was the presence of demonstrators from many countries. Nor was the event's impact short-lived: in June 1999 marches took place involving some 30,000 people in protests against the European Summit in Cologne. This chapter will first examine the conditions for the emergence of a most unexpected movement. It attempts to show how a small number of entrepreneurs, despite the weak support of the institutional representative frameworks, gave colle...