We provide a synthesis of the long-term earthquake activity in the region of northwest Europe between the Lower Rhine Embayment and the southern North Sea. Reevaluated historical earthquake and present-day seismological data indicate that much of the known seismic activity is concentrated in the Roer graben. Nevertheless, the three strongest known earthquakes with estimated magnitude ≥ 6.0 occurred outside of this active structure, in the northern Ardenne, the southern North Sea, and the Strait of Dover. During the past 700 yr, destructive earthquakes generally have occurred at different locations, indicating a migration of seismicity with time. Because in plate interiors...