This paper analyses the strategies adopted to address political uncertainty by several major late medieval political thinkers. It focuses on: 1) Thomas Aquinas’ treatment of whether, and when, it is appropriate to overthrow a tyrant; 2) Marsilius of Padua’s conception of peace as a precarious and fragile condition that must be defended daily amid the relative insecurity that characterises every human society; 3) John Wyclif’s doctrine of grace-based dominium and his ecclesiology, which require seeking stable points of reference by which to formulate valid assessments about who holds genuine lordship and the composition of the true church; and 4) John Fortescue’s analysis of the economic impact of different forms of government, grounded in the conviction that people’s economic security is better protected in a «political and royal» constitutional regime – that is, a temperate monarchy.
Keywords: Uncertainty, Tyranny, Peace, Invisible Church, Property Rights.