The purpose of this paper is to outline the conceptual framework of the project on "The Performance of European Business in the Twentieth Century," present some of the project's initial findings, and start a debate on the issue of performance among business historians. We launched the project to fill a major gap in the business history literature. It provides a comparative analysis of business performance in seven key European economies: Belgium, Britain, France, Germany, Italy, Spain, and Sweden. We preview the outcome of the project in this pilot study using the first and the last observation years: 1913 and 2000. We focus on two key measures of performance: return on equity and holding return, two complementary measures which can move in opposite directions (for example in 1913, an annus horribilis for investors despite high returns on equity). Our intent is to confront these results with qualitative data on a number of individual companies, making use of a prosopographical approach. Exploring the potential of integrating the history of the firm into a collective analysis of business performance should provide business history a contribution to the theme of performance, distinct from that of economics, accountancy, or business strategy.