In the paper the author analyzes the historical models of assistance to the poor, focusing on the major institutional reforms. In particular, starting from the Italian Unification it considers the main steps that led to the affirmation of the principle of proximity in the care of the interest, under which the management of social services is awarded to municipalities. Taking into account the results of the Constitution and the difficulty of the state to fully protect the right to assistance, the law 328/2000 and the Reform of Title V of the Constitution have ordered the "horizontal" subsidiarity. A principle that encourages private participation in the planning and management of the welfare activities, allowing a full implementation of the most general instances of solidarity.
Keywords: Social services, solidarity, welfare mix