The introduction of income taxation was a landmark in the development of the fiscal state in Western Europe and elsewhere. This paper presents an event history study of the adoption of the income tax in 11 Western European countries between 1815 and 1941. We find evidence that social learning, reductions in tax collection costs and to a lesser extend spending pressures played a significant role for the adoption decision. Surprisingly, we also find evidence that the extension of the franchise reduced the likelihood of adoption of the income tax.