Evidence of the first urban settlements can be traced back a couple of millennia. Until the end of the 18th century, however, cities remained relatively small in size and contained a small proportion of the overall population. However, from this point onwards, the process of urbanisation - the movement of people from the countryside to the city and the rapid development of the built environment and urban infrastructures - accelerated in conjunction with industrialisation. In Western countries, cities became the drivers of regional and national economies and the proportion of the population living in urban settlements rapidly increased throughout the nineteenth and twentieth century. At present, we are witnessing an economic slow down in the developed and largely urban economies of North America and Europe and unprecedented growth in South America, Africa and especially in the rapidly growing economies of Asia. These Asian Tigers are also experiencing mass rural-urban migration, as their citizens search out employment opportunities and better living standards for themselves and their families. Indeed, the global urban population is forecast to more than double by 2050, turning the human condition into an urban condition, with more than 90% of this larger urban population being accommodated in developing countries. Europe is already around three-quarters urbanised and its citizens enjoy, on the whole, high standards of living and good access to healthcare and welfare services. However, public services are deteriorating and the welfare state is being eroded; inequalities are rising; the population is aging; and the livelihoods of cities are becoming increasingly sensitive to the vagaries of extreme weather events. Urban governance is facing new and multi-scale challenges and responding to these effectively may require hitherto unknown degrees of cooperation and indeed co-creation, as urban settlements gear up to accommodate these challenges. Effective decision making will also be contingent upon a comprehensive and holistic understanding of how cities function and of which types of strategy for change will be most effective at achieving targets that better articulate social, economic, political and environmental aspirations. Renewed approaches to urban research and to urban governance are required to address these multifaceted challenges and the changing nature and scale of the “urban”: from cities and urban agglomerations to wider urban regions; increasingly subject to flows of energy, materials, information, finance and people. In this report we discuss these changes and the challenges facing urban societies, with a view to identifying the most relevant and pressing research and innovation priority areas. We begin by discussing global trends, focussing initially on the interrelated processes of demographic change, globalising economies, social inequality, technological innovation and environmental change; identifying broad global challenges. We then focus on the role cities play, how they are affected by these global trends and at the same time how they contribute to shape them. In the second part of the report, we examine the challenges and opportunities associated with these global trends within the European context, highlighting the impacts of political and economic transitions as well as the pressing agenda for climate change adaptation and mitigation. We then reflect on the main facets of city functioning (the drivers of urban economies and revenues; how cities metabolise their resources: energy, matter, finance, information; the infrastructures and services that support and drive these metabolic processes; the dynamics of urban societies) and on the interactions between these dimensions. In the fourth, concluding part of this report, we identify some of the key challenges that need to be addressed by the European urban research community in the short to medium term and outline a research framework by which they may be realised, throughout the lifecycle from basic research advances through to their translation into utilisable techniques and technologies and actionable policy measures.