Academic inbreeding is a deeply ingrained practice which needs to be understood by reference to the medieval guilds. Drawing on the guild concept and associated benefits of forms of capital, a distinction is drawn between ‘guild-route’ academics who have followed a privileged, linear path into academe and their ‘non-guild’ counterparts who tend to enter later in their career from the professions or industry, often without a PhD. The tendency to represent early career researchers from a guild background as members of an academic proletariat is largely misleading and fails to take account of their privileged entrée into academe. Their experience is contrasted with those recruited via the non-guild route who do not have the benefits of the valued social, cultural or symbolic capital needed to advance their careers. Policy implications are discussed to better understand the effects of academic social class on recruitment practices in universities. Copyright © 2021 The Authors. Higher Education Quarterly published by John Wiley & Sons Ltd.