Although it was only in the course of the nineteenth century that the barricade emerged as the preeminent symbol of the modern revolutionary tradition, its origins can be traced as far back as sixteenth-century France.The great cyclical peaks in the history of French contention—the “Day of the Barricades” in Paris in 1588, the second “Day of the Barricades” in 1648, and the revolutions of 1789, 1830, and 1848—mark major turning points in the evolution of this technique of insurrection. They succeeded in transforming a custom that had remained exclusively French for the first two hundred years of its existence into a pan-European phenomenon.The remarkable persistence and eventual diffusion of barricades must be understood in terms of the crucial functions they perform in insurrectionary situations. The most obvious are practical in nature and help explain the tactic’s initial adoption: providing cover for insurgents on the one hand, and serving to isolate troops and prevent their free circulation on the other.Less evident, but no less essential, are a series of sociological functions that include mobilizing the population and attracting new recruits to the insurgent cause, building solidarity among participants and helping them to gauge their chances of success, identifying leaders and facilitating the emergence of an efficient division of labor among the barricade’s defenders, and making it possible for insurgents to fraternize with soldiers and police in an effort to sway their loyalties.In the modern era, after the military began to make systematic use of artillery and experimented with new strategies for the repression of civil unrest, the purely pragmatic utility of the barricade diminished. But the barricade’s symbolic functions became more prominent, highlighting the central role of barricades in a culture of insurrection that gradually assumed global proportions.