The main ambition of TAILOR is to build the capacity of providing the scientific foundations for Trustworthy AI in Europe by developing a network of research excellence centers with a technical focus on combining research excellence in the areas of learning, optimisation and reasoning . The current scientific landscape is fragmented with many research groups working individually or in smaller constellations in often relatively isolated scientific communities: machine reasoning, machine Learning, and optimization are examples of such mostly-disjoint communities all working on different aspects of Trustworthy AI. The TAILOR project brings these groups together in a single scientific network thereby reducing the fragmentation and increasing the joint AI research capacity of Europe to take the lead and advance the state-of-the-art in Trustworthy AI.