The Bellagio process led to the Bellagio Declaration, a set of principles for how to ensure that any system for monitoring the transition to a circular economy captures all relevant aspects and involves all relevant parties. The work began as a collaboration between the Italian Institute for Environmental Protection and Research (ISPRA) in Italy and the European Environment Agency (EEA), guided by an advisory group encompassing the Network of the Heads of European Environmental Protection Agencies' (EPA Network) representatives from Finland, Ireland, the Netherlands, Portugal and Slovakia.