Each step in the development of the bourgeoisie was accompanied by a corresponding political advance of that class. An oppressed class under the sway of the feudal nobility, an armed and self-governing association in the medieval commune: here independent urban republic (as in Italy and Germany); there taxable “third estate” of the monarchy (as in France); afterwards, in the period of manufacturing proper, serving either the semi-feudal or the absolute monarchy as a counterpoise against the nobility, and, in fact, cornerstone of the great monarchies in general, the bourgeoisie has at last, since the establishment of Modern Industry and of the world market, conquered for itself, in the modern representative State, exclusive political sway. The executive of the modern state is but a committee for managing the common affairs of the whole bourgeoisie.
Bourgeois revolution, in historical materialism, is a type of social revolution in which the superstructure of a feudal state is replaced by bourgeois society, and the conditions laid for the eventual dictatorship of the bourgeoisie. Karl Marx identified at least four bourgeois revolutions in his writings: the Dutch Revolt, the English Revolution, the American Revolution, and the French Revolution. Marx saw these as sharing crucial elements: all four occurred in the period after the discovery of the Americas and the rounding of the Cape, direct catalysts for the rise of the European bourgeoisie; each was followed by a golden age in the history of their respective countries; each instituted, or attempted to institute, a republican form of government, as well as cementing legal rights imicable to the rule of the bourgeoisie; and each was carried by a mass movement of people of the lower classes, such as yeomen, journeymen, and wage workers, united by grievances against the ruling class. Following the language used by the French revolutionaries as well as by bourgeois historians, Marx used the term 'feudal' to describe the relations of the regimes overthrown by the bourgeoisie.
But unheroic though bourgeois society is, it nevertheless needed heroism, sacrifice, terror, civil war, and national wars to bring it into being. And in the austere classical traditions of the Roman Republic the bourgeois gladiators found the ideals and the art forms, the self-deceptions, that they needed to conceal from themselves the bourgeois-limited content of their struggles and to keep their passion on the high plane of great historic tragedy. Similarly, at another stage of development a century earlier, Cromwell and the English people had borrowed from the Old Testament the speech, emotions, and illusions for their bourgeois revolution. When the real goal had been achieved and the bourgeois transformation of English society had been accomplished, Locke supplanted Habakkuk.— Karl Marx, The Eighteenth Brumaire of Louis Bonaparte
Role of the lower classes
The “have-nothing” masses of Paris, during the Reign of Terror, were able for a moment to gain the mastery, and thus to lead the bourgeois revolution to victory in spite of the bourgeoisie themselves. But, in doing so, they only proved how impossible it was for their domination to last under the conditions then obtaining. The proletariat, which then for the first time evolved itself from these “have-nothing” masses as the nucleus of a new class, as yet quite incapable of independent political action, appeared as an oppressed, suffering order, to whom, in its incapacity to help itself, help could, at best, be brought in from without or down from above.— Friedrich Engels, Socialism: Utopian and Scientific