The 15-year-long resistance to Shell’s pipeline project in NW Ireland has become a strategic and symbolic site for resistance to neoliberalism and the petroleum industry, rooted in the combination of a community-based environmental justice struggle with the long-term involvement of a range of Irish social movements of the left and the intensive commitment of a substantial number of primarily international ecological activists. The movement faced the external challenges of extensive state violence and media demonisation of participants as well as the internal ones of divisions within the community, tensions between ecological and redistributive movement priorities and the instrumental attitude of some political parties and unions; despite this the campaign was very long by international standards, forced some substantial changes to state policy and has contributed to anti-austerity alliance formation and popular learning processes in the resistance to fracking, as well as to raising the political and financial cost of such projects massively. If it ultimately failed on its own terms, international comparison suggests that this had far more to do with the balance of forces against it than with internal difficulties. As against the assumption that social or ideological differences within a campaign are a source of inevitable doom (and the more banal assumption that unity is everything), this chapter explores the ways in which broad cohesion can be maintained despite such pressures. It highlights the internal learning processes of an initially conservative rural community over time; how the early imprisonment of 5 locals enabled the national left to support a campaign ‘led by the families’ rather than jockeying for leadership themselves; why the desertion of the campaign by parties in power did not lead to its collapse; and how Irish movements managed to educate international activists sufficiently that they and the community could work together effectively over time. It also questions simplistic notions of success and restates the importance of sustained popular mobilisation, learning through action and alliance formation as key elements of the potential needed to bring about a better world. The chapter frames this discussion in relation to Gramsci’s discussion of the formation of diverse kinds of subaltern knowledge and organisation and contemporary Marxist discussion of alliance-formation processes in social movements. The chapter draws on discussions with activists in the campaign about their understandings and strategies in the process of resisting Shell, and seeks to draw out useful lessons for comparable campaigns elsewhere. A note on the complex, changeful nature of gas and oil ownership during this campaign: the Corrib gas field was discovered in 1996 by Enterprise Oil who continued as co-venturers on the Corrib project with Statoil and Marathon, until Royal Dutch Shell purchased their majority stake in 2002. Shell, Statoil and the Canadian group Vermilion, who bought out Marathon in 2009, continue as stakeholders, with Shell E&P as the operator and main shareholder on the project. The community led campaign understood early on the importance of selecting a clear target, given the corporate context of buyouts, merging and rebranding. In the wake of nationwide boycotting and picketing of Shell owned petrol stations, in solidarity with the community struggle, Shell was forced to sell its entire retail and commercial business in Ireland to Topaz.