Homelessness is the most extreme form of housing and social exclusion. Homelessness has emerged as a pressing challenge, in view of the increasing number of homeless people in many - but not all - OECD countries. At the European level, homelessness has moved up on the policy agenda over the past decade, and notably figures in Pillar 19 in the European Pillar of Social Rights, adopted in the autumn of 2017 which calls for adequate shelter and services to be provided to the homeless in order to promote their social inclusion.