May 1967, in Nigeria, the Republic of Biafra declared its independence. Soon, civil war and famine ravaged the region and gradually entered the European and American media. Photographs of the conflict arouse considerable emotion in the West. The secessionist enclave and the areas taken over by the Nigerian army then became the scene of major relief operations, developed and financed by multiple organizations and governments. Part of a historiography of humanitarianism in full renewal, this book tells the story of the war, its metamorphosis into an international crisis and the responses that were provided. Based on a large body of sources from French, British, Swiss, Nigerian and American archives, it offers an insight into the world of humanitarian work at the end of the 1960s. It shows the reconfigurations taking place there. in the postcolonial era by proposing complementary scales of observation - international, national and local. The work also revisits some of the controversies which developed around the conflict regarding the instrumentalization of aid, its links with politics, the reception of relief operations on the ground or even the birth of borderlessness and testimony. It thus returns to the place occupied by the Biafran crisis in the history of humanitarian aid.