In seeking to understand inequality today, a great deal can be learned from history. However, there are few countries for which the long-run development of income inequality has been charted. Many countries have records of incomes, taxes and social support. This paper presents a new methodology constructing income inequality indices from such data. The methodology is applied to Norway, for which rich historical data sources exist. Taking careful account of the definition of income and population and the availability of micro data starting in 1967, an upper and lower bound for the pre-tax income Gini coefficient is produced.