Focusing on the period from 1870 to 1960, this chapter provides an overview of anarchist approaches to anti-imperialism, offering examples of collaborations, solidarities, antagonisms and syntheses between anarchists and anti-colonialists from across the British, Spanish, French and Portuguese colonial worlds and within the imperial metropoles in Europe. Alongside anti-colonial resistances to these processes, anarchists were central to the development of an anti-imperial political modernity within the European left as well as across the colonial worlds. In fact, as this chapter illustrates, anarchism was inherently anti-imperial in its demands for individual freedom and insistence on dismantling the power structures that governed European colonial policies. Exploring core principles of anarchist anti-imperialism with a vision of postcolonial societies, the chapter discusses issues of nationalism and the nation-state, anti-statism and political organisation, exile and diaspora, anti-capitalism and boycott. In doing so, it pays particular attention to theory and praxis, ideological sympathies and revolutionary methods, including terrorism, insurrection and sabotage. Within these discussions, the chapter highlights antagonisms and incompatibilities among and between anarchists and anti-colonialists, allowing for an assessment of the limitations of anarchism within the anti-colonial context.