A problem for both historical and contemporary research on inequality is a scarcity of high quality data on wealthy households. In this paper we explore a rich source of such data for historical periods: the account books of aristocratic households preserved in their family archives. We make three contributions: i) a survey of the nobility in Italy and of their publicly accessible archives; ii) an assay of the type and quality of budget data they contain; and iii) an assessment of the impact of adding upper-tail families to a household budget sample on inequality estimates. In a nutshell, our assessment is that the data are relatively abundant, accurate, and highly impactful. An enhanced sample of noble families will enable us to significantly improve estimates of Italian inequality right back to the country’s founding in 1861. There is no reason to think the approach would be any less feasible or fruitful in other European countries.