Revolutionaries and scholars alike have noted the recurrence within capitalism of “waves” of large-scale social movement mobilisation and revolutionary situations, including the C18th Atlantic Revolutions, the Latin American wars of independence, the events of 1848 in Europe, the events of 1916-23 in Europe and North America, resistance to fascism in Europe and Asia, anti-colonial uprisings in postwar Asia and Africa, the events of 1968 across the northern hemisphere and the events of 1989 in the Soviet bloc and China. At present the overlap of a global “movement of movements” with the Latin American “pink tide”, the anti-war movement of 2003, anti-austerity and Occupy movements in the global North and the uprisings in the Middle East and North Africa suggest that another such wave is underway. This paper attempts to understand the broad historical experience in ways that are relevant to the present and enable effective action. It proposes an analysis of such waves as occurring within one or more regions of the capitalist world-system and involving an organic crisis of a particular regime of accumulation – entailing a growing popular capacity for action, the detachment of subaltern elements of the previously hegemonic coalition and a declining elite capacity to either offer significant concessions or to mobilise effective repression. By placing the analysis at this level it avoids the superficial requirement that such waves share a common popular actor or set of demands – what similarities exist in terms of leading popular actors and modes of organisation are to be explained by this broader situation (notably, the difficulties experienced by the existing regime of accumulation in accommodating given needs and social groups). It also makes it clear that a revolutionary outcome is by no means a given, nor is it a requirement for a “real” wave. However the historical experience has often been that even where a given regime was able to recover temporarily in the longer term a new set of hegemonic arrangements, incorporating some movement demands, has been necessary. In relation to the present crisis, with its multiple popular actors, this analysis suggests particular attention to the weaknesses of neoliberalism in securing continued hegemony – and to demands, and popular institutions, which accentuate this. It notes in particular the length of this crisis, which is historically unusual and politically encouraging, as is the narrowness of neoliberal orthodoxy and the difficulties experienced in finding new modes of organisation to incorporate popular pressures. It concludes with some suggestions as to what movements can do in this situation.