While territories have always faced multiple challenges, the addition of ecological transition to economic, cultural and social issues complicates matters considerably. Transition calls for new perspectives.

The reinvention of territories through solidarity appears to be a particularly relevant approach as it allows us to draw on the many innovations brought about by players in the social and solidarity economy (SSE). To illustrate this point, the book brings together case studies that bear witness to their astonishing ability to link the economy and local democracy to ensure the sustainability of their activities. These case studies illustrate a renewed vision of territorial development based on cooperation between the SSE, local authorities, entrepreneurs and citizens. Subsequently, they usher in a new way of thinking about public action, in which solidarity players undertake an important role, in co-constructing with local public players, systems capable of meeting the major challenges of our time.