In this paper I discuss Foucault's two recently published courses, Sécurité, Territoire, Population and Naissance de la Biopolitique. Foucault notes that he has undertaken a genealogy of the modern state and its different apparatuses from the perspective of a history of governmental reason, taking into account society, economy, population, security, and liberty. In the "Governmentality" lecture - the fourth of the first course - Foucault says that the series of the title - that is, security, territory, population - becomes "security, population, government". In other words, territory is removed and government appended. And, yet, the issue of territory continually emerges only to be repeatedly marginalised, eclipsed, and underplayed. A key concern of the course is the politics of calculation which Foucault discusses through the development of political arithmetic, population statistics, and political economy. Explicitly challenging Foucault's readings of Machiavelli and the Peace of Westphalia, I argue that territorial strategies should themselves be read as calculative, with the same kinds of mechanisms brought to bear on populations applied here too. I therefore discuss how Foucault's discussions of political economy, the police, and calculation are useful in thinking the history of the concept of territory.