A general introduction to the doctrine of self-determination in international law. Self-determination is historically contextualised from its intellectual progenitors in the Enlightenment through to its political birth at the 1919 Paris Peace Conference and its formal induction into international law by virtue of the 1945 UN Charter. Both the detail of the doctrine's content and the dynamic governing its development are explored. The relationship between self-determination and state formation (including decolonisation and secession), minority rights, aboriginal rights, women's rights and the nascent right to democratic governance are central topics.