By 1920 the rule of the British Authorities was collapsing in Ireland, with many local governments controlled by Sinn Féin, and the police force being in Ireland needing to be reinforced with auxiliary police such as the Black and Tans. The UK government passed the Restoration of Order in Ireland Act, which replaced civil with military powers. Martial Law was declared in a number of counties in Munster, eventually allowing for the internment without trial and even execution of any Irish citizen.
