Accounting practices played a fundamental role in the construction of Brunelleschi's dome of Santa Maria del Fiore in Florence during the fifteenth century. This study examines the accountability practices and government technologies adopted by the Opera del Duomo, the organisation entrusted to build and maintain the Cathedral of Florence, between 1420 and 1436, when the dome was constructed. This research draws on the theories of Foucault and Dean regarding technologies of government within quasipublic administrations to explain historical evidence for the accountability practices supporting Brunelleschi's dome construction. Through the collected evidence, we identify the application of 'technologies of government' hundreds of years before Foucault's arguments about governmentality. We also describe a system of accountability, especially downward accountability, inspired by religious values that pays attention to users, the local community and other affected constituents as a result of the Opera's special status as a 'quasi-public' (but formally private) administration. Our findings touch on the willingness to account for and report public funding, the presence of checks and balances inside the governance framework, the active engagement of citizens and local partners to achieve consensus, and notions of social responsibility toward the workers who helped to build the dome.