 The paper calls for a synthesis of two approaches to understanding flood regime changes in European rivers, database detection of changes in observed flood events and modeled scenarios of future floods. To make progress, the paper suggests focusing on long-duration records, formally attributing causes of observed flood changes, validating scenarios against observed flood regime dynamics and developing low-dimensional models of flood changes and feedbacks. The paper concludes with a call for a joint European flood change research network. This article was authored by J. Hall, B. R. Heimer, M. Borga, and others.