The study of the Middle East, and of the Gulf monarchies in particular, is generally dominated by institutionalist and neo-Weberian approaches focusing on religious identity, sectarianism, authoritarianism or natural resource endowment as key explanatory factors underlying social processes in the region. In these accounts, the notion of class often disappears from view or is loosely elided with anachronistic or imprecise labels such as ‘merchants’ and ‘elites’. This chapter reflects on how Marxist conceptualisations of class can help in grasping the specificities of labour, migration and capital accumulation in the Gulf – not least in thinking about how the social relations underlying these categories extend across national borders with profound implications for the surrounding region. This is much more than simply an issue of theory; Marx's work can be a powerful guide to doing field research in the Gulf – revealing the right questions to ask and helping unearth surprising connections that might otherwise have gone unnoticed. The analysis draws on the author's experience of several years of living and research in the Gulf; conducting interviews with businesspeople, migrant workers and other key informants; teaching Gulf women citizens and, overall, trying to grasp – in the field, with Marx – the nature of capitalist accumulation in the Gulf.