Testing articles made of precious metals and stamping them with hallmarks to indicate they are of a minimum standard of purity has been carried out by the Worshipful Company of Goldsmiths for seven centuries. The minute books of the Company, the core of the present study, provide an almost unbroken record since the 1330s, and names prominent in the Company's affairs include Isaac Newton, Charles II, Paul de Lamerie, the Vyners and the Garrards.