Due to its past colonial status, Ireland has strived to oppose its national identity to the heritage of British rule as it gradually severed ties with its former rulers. Nationalism being a political notion, it is normally reflected in the country's institutions, the latter getting their legitimacy by constitutional means, and this is how the national/foreign, and identity/interculturality dichotomies were shaped. This paper will examine a particular case of these oppositions in the context of the first Republic (1919–1923) whose judicial institutions competed with the existing British court system during the War of Independence, under the tutelage of Gilles Deleuze and Félix Guattari's political and philosophical critique of the State (A Thousand Plateaus, 1980). It will deal with the setting up of a system of courts, called the Dáil Courts, and how they came to represent some sort of Irish identity in the making, something that Deleuze and Guattari called a " becoming " , while aggregating both British and foreign legal features. The fate of this singular system will first be examined as the setting up of a Deleuzian war machine challenging the rigid structure of the colonial State apparatus (1919–1920); the second part will analyse how the new court system efficiently replaces the old institutions by adopting an unusual " rhizomatic " structure (1920–1921); finally, the third part will show how the Dáil Courts were absorbed by the Irish Free State's Apparatus of Capture that reinstated a more familiar, traditional Common Law system (1921– 1924).