In most societies, courts are where the rubber of government meets the road of the people. If a state cannot settle disputes and ensure that its decisions are carried out, for practical purposes it is no longer in charge. This is why successful rebels put courts and justice at the top of their agendas. Rebel Law examines this key weapon in the armory of insurgent groups, ranging from the Ireland of the 1920s, where the IRA sapped British power using 'Republican Tribunals' to today's 'Caliphate of Law' -- the Islamic State, by way of Algeria in the 1950s and the Afghan Taliban. Frank Ledwidge tells how insurgent courts bleed legitimacy from government, decide cases and enforce judgments on the battlefield itself. Astute counterinsurgents, especially in 'ungoverned space,' can ensure that they retain the initiative. The book describes French, Turkish and British colonial 'judicial strategy' and contrasts their experience with the chaos of more recent 'stabilization operations' in Iraq and Afghanistan, drawing lessons for contemporary counterinsurgents. Rebel Law builds on his insights and shows that the courts themselves can be used as weapons for both sides in highly unconventional warfare.