The historiography of elite women has often contrasted ‘power’, the effective ability to command and be obeyed, with ‘authority’, the sanctioned right to lead. Using Jeanne’s charters as an idealized projection of her actual position, this chapter argues that this model is too restrictive to reflect contemporary understandings of lordly roles. On the surface, these texts seem to associate Jeanne with ‘authority’ and Charles with ‘power’, but a closer examination reveals that neither authority nor power was monolithic: different types of authority coexisted with different types of power, and all could vary jointly or independently. Moreover, these concepts were not static points of reference, but were actively manipulated by contemporaries according to various social norms. This suggests that instead of using the power/authority dichotomy, a more effective model of power dynamics would account for both the people or things over which power was exerted, and the practical and ideological grounds on which it worked. Approaching power from this contextually specific angle enables more diverse comparisons by privileging no single explanatory factor, aim, or outcome of power, and gives greater insight into the complexity of medieval political structures and their social functions.