To understand the complex Earth System requires an integrated observational strategy and infrastructure to record key diagnostic features of its dynamics. Accordingly, this infrastructure must include geographically distributed and multidisciplinary monitoring instruments and observations. The European Plate Observing System (EPOS) will meet this challenge. The proposed RI (EPOS) will create a single sustainable, permanent and distributed infrastructure, integrating land-based geophysical monitoring networks, local observatories (including permanent in-situ and volcano observatories) and experimental laboratories in Europe. EPOS will give open access to geophysical and geological data and modelling tools, enabling a step change in multidisciplinary scientific research into different fields, including seismic and volcanic hazards, environmental changes as well as energy and long-term sustainability. This will result in benefits to society.Presently, the different European countries own a mosaic of hundreds of impressive, but separated networks, observatories, temporary deployments, labs and modelling facilities, etc... for solid earth studies. Long-term sustainability of plate observations, optimising access to, and combining a wide variety of solid Earth data and modelling tools are prerequisites to innovative research for a better understanding of the physical processes controlling earthquakes, volcanic eruptions and other catastrophic events (landslides, tsunamis) together with those controlling Earth surface dynamics (crustal response to deformation and to global change). EPOS will enable the scientific community to study the same phenomena from a multidisciplinary point of view, at different temporal and spatial scales (from laboratory to field and plate tectonic scale experiments). EPOS intends to create the prerequisites for Europe to maintain a leading role in solid Earth science research.