In this chapter, the author summarises how Marxist theory relates to urban areas and describes the evolution of this body of thought during the post-war period. For Marxists, modern cities are “capitalist cities”, not merely “cities in a capitalist society”, and are shaped in key respects by the dynamics of capitalist accumulation. It is within this context that Marx confronts the specificity of the capitalist city, arguing that the distinction between city and countryside is a constitutive element of the capitalist division of labour. The specificity of urban areas rests with the ways in which they bring together labour, capital and land to form a dynamic and spatially-uneven configuration of productive resources. The approach developed by Marx and Engels explains the historical development of urban areas by referring to the transformations generated by capitalist relations of production in agriculture and manufacturing. The former is theorised in terms of “primitive accumulation” – the expropriation and enclosure of common lands – which led to the exclusion of agricultural labourers from the means of agricultural production, whilst the latter entailed a rapid expansion in the demand for labour in the industrial centres.