EUDAT is our proposal for the next stage in the realisation of the vision of "data as infrastructure". The EUDAT consortium includes representatives from each stage of the value chain that has evolved to deliver scientific knowledge to researchers, citizens, industry and society as a whole. It includes funding agencies that invest in research infrastructures and programmes of research, infrastructure operators and research communities who rely on the availability of data-management services, national data centres and providers of connectivity and, of course, the users who rely on the availability of data and services, innovators who add value to the raw results of scientific research.EUDAT is a three-year project that will deliver a Collaborative Data Infrastructure (CDI) with the capacity and capability for meeting future researchers' needs in a sustainable way. Its design will reflect a comprehensive picture of the data service requirements of the research communities in Europe and beyond. This will become increasingly important over the next decade as we face the challenges of massive expansion in the volume of data being generated and preserved (the so-called 'data tsunami') and in the complexity of that data and the systems required to provide access to it.Although those user requirements will vary between scientific disciplines, the micro-systems from which each community's services are built are largely generic. This commonality will make it easier to achieve the minimum critical mass of users necessary for significant economies of scale to be achieved. The ability to rapidly provide bespoke responses to the evolving needs of our research communities additionally strengthens the business case for those communities. With the inclusion of disciplines from across the spectrum of scientific endeavour sharing a common infrastructure, EUDAT also provides the opportunity for data-sharing between disciplines and cross-fertilisation of ideas.