This paper describes the evolution of capital income taxation in Sweden between1862 and 2013, including the taxation of corporate profits, dividends, capital gains, interestincome, and wealth taxation. To illustrate this evolution, we present annual time-series dataregarding the marginal effective tax rates on capital income (METR) for a marginalinvestment financed with new share issues, retained earnings or debt. The METR is low andstable and does not exceed five percent until World War I, when it begins to drift somewhatupward and vary depending on the source of finance. The outbreak of World War II begins aperiod during which the magnitude and variation of the METR sharply increase. The METRpeaks during the 1970s and 1980s and often exceeds 100 percent. The 1990–1991 tax reformand lower rates of inflation reduce the magnitude and variation of the METR, which variesbetween 15 and 35 percent at the end of the period examined.