Environmental and land conflicts in Tamou (Niger): the powers involved - The territorial conflict in the rural municipality of Tamou (Niger) is the result of a complex dynamics begun in the colonial period and regarding land tenure, environment, and even politics and institutions. Starting from the historical reconstruction of the settlement process of the social groups now living in the municipality, we proceeded to identify the nucleus of authority of the traditional legitimacy from which the different basic geographical configurations of the area of Tamou were structured. The paper also reconstructs the transformations, the evolutions and the disorders that have affected these nuclei of authority through the phases of Islamization, colonialism and the different political phases of the independent State of Niger, until the current politico- institutional evolutions that see Niger engaged in the process of decentralization. Finally, the aim of this paper consists firstly in identifying the traditional Institutions of authority that are still legitimating power; secondly, in analyzing the historical dynamics that have lead to the present situation of conflict. Particular emphasis is given to the networking process regarding the actors of legitimacy and legality, and to the proliferation of issues, partly determined by the ongoing process of decentralization.