The science of complex systems is crucial to FET and the economic success of Europe. But complex systems research is still not well coordinated in Europe, with urgent need to connect and expand the community. This three-year CA coordinates and integrates scientific research and dissemination in the European CS community by (i) identifying fundamental questions across CS in all areas of application, in order to ground the new science, (ii) encouraging and facilitating research collaboration around the fundamental questions, to stimulate research and applications across academic disciplines, industry and government, (iii) establishing sustainable cross-disciplinary education in CS science, (iv) coordinating the creation of a European PhD in CS science, (v) supporting European Centres of Excellence in CS science, (vi) providing network infrastructure for the new Integrated Projects and connecting them and the CS community, and (vii) coordinating the formation of a vigorous self-sustaining European Complex Systems Society (ECSS), to take over the networking and coordinating roles of Exystence and ONCE-CS. All this is enabled by (viii) the provision of a robust and well-designed Internet portal providing many delivery, retrieval, communication, and management services.