Urban historians, particularly those of the medieval and early modern periods, have been concerned to identify the leading members of town society and to judge their political and socio‐economic influence. Some corporations were difficult for newcomers to penetrate, but the industrial towns such as Birmingham and Sheffield were much more open. Historians have also examined the ways in which elites were linked through marriage, religion, and business connections by constructing detailed biographies; see, for instance, R. G. Wilson, Gentlemen Merchants: The Merchant Community in Leeds, 1700–1830 (1971). They have also analysed the membership of governing bodies and have searched for evidence of clashes between elites and the governed. See Peter Clark and Paul Slack, English Towns in Transition, 1500–1700 (1976), ch. 8.