The science of materials has always been at the centre of scientific and technological progress in human development. The tools to understand materials that fashion them to meet our societal needs have been just as important. Thermal neutrons are one of the most powerful probes that look directly at the structure and dynamics of materials from the macro- to the microscopic scale and from nano-seconds to seconds. It is therefore natural that a group of 17 European Partner Countries have joined together to construct the world’s most powerful neutron source, the European Spallation Source (ESS). The importance of ESS has been recognised by ESFRI who have prioritised it as one of three Research Infrastructures (RIs) for this INFRADEV-3 call. However, simply constructing the most powerful spallation neutron source will not, by itself, ensure the maximum scientific or technological impact. What is needed is an integrated program that ensures that key challenges are met in order to build an ESS that can deliver high impact scientific and technological knowledge. With a timeline of 36 months, involving 18 Consortium Partners and a budget of € 19.941.964, the BrightnESS proposal will ensure that (A) the extensive knowledge and skills of European companies, and institutes, are best deployed in the form of In-Kind Contributions to ESS for its construction and operation, (B) that technology transfer both to, and from, the ESS to European institutions and companies is optimised and, (C) that the maximum technical performance is obtained from the ESS target, moderators and detectors in order to deliver world class science and insights for materials technology and innovation.