Scottish nationalism is a powerful movement in contemporary politics, yet the goal of Scottish independence emerged surprisingly recently into public debate. The origins of Scottish nationalism lie not in the medieval battles for Scottish statehood, the Acts of Union, the Scottish Enlightenment, or any other traditional historical milestone. Instead, an influential separatist Scottish nationalism began to take shape only in the 1970s and achieved its present ideological maturity in the course of the 1980s and 1990s. The nationalism that emerged from this testing period of Scottish history was unusual in that it demanded independence not to defend a threatened ancestral culture but as the most effective way to promote the agenda of the left. This accessible and engaging account of the political thought of Scottish nationalism explores how the arguments for Scottish independence were crafted over some fifty years by intellectuals, politicians and activists, and why these ideas had such a seismic impact on Scottish and British politics in the 2014 independence referendum.