Social democracy only entered the European political lexicon in the 1870s, but there were earlier references to the term. Following the 1848 revolution, which established France's Second Republic, the word social democrat referred to the coalition between the republicans of the Mountain (La Montagne) and democratic socialists (Moschonas 2002: 17). However, its usage was rather limited across Europe. Far more common was the term socialism, of which several varieties existed.

More importantly, the term social democracy was used in a derogatory fashion by communists and revolutionary socialists. For example, in “The Eighteenth Brumaire of Louis Bonaparte”, Karl Marx explained that democratic socialists known as the La Montagne had drafted a programme that had removed “the revolutionary sting” from “the social demands of the proletariat” (Marx 1996 [1852]: 38). The implication of this was that social democracy was merely about “the reform of society in a democratic way, but a reform within petty-bourgeois limits” (Marx 1996 [1852]: 59). In short, social democracy was a bourgeois project. But as Friedrich Engels admitted in 1894, “things are different, and this word may perhaps do the job even though it remains inexact” (Engels quoted by Lenin 1992 [1917]: 7). Leaving aside Engels's concerns about its exact semantic value, what is clear is that by the 1870s social democracy not only came to mean something very different from its earlier reformist connotations but it also gained wider currency within European radical political circles.

This chapter charts the emergence of social democracy as a political movement and ideology in Europe from the 1870s. It starts by briefly explaining the political, social and ideational context in which it emerged. Next, it maps its beginnings from the foundation of the first social democratic party – Germany's Social Democratic Workers’ Party – to the spread of social democratic parties across Europe. The chapter also examines how social democrats navigated the doctrinal tensions created by their entry into electoral politics. Debates about conquering political power through the ballot box, the prospect of revolution or the promises of reform, and the potential cooperation with liberal parties gradually transformed social democracy. Finally, the chapter explains the impact of rising nationalism in Europe, the First World War and the Bolshevik Revolution on social democracy.

Along the way, the chapter shows that social democracy did not evolve in a neat and linear form in the European continent.