Ontario's provincial-municipal relationship is the most entangled and complex in Canada. The Ontario government, in collaboration with the Association of Municipalities of Ontario, has launched a process known as disentanglement to reform that relationship. Disentanglement refers to the unravelling of responsibilities now shared by governments in order to achieve delivery of services that is more accountable, efficient, and effective than at present. This report makes two contributions to the disentanglement process. The first is a brief history of provincial-municipal relations in Ontario with particular reference to previous attempts at clarifying provincial and municipal roles. Reforms of the late 1960s-early 1970s are covered in detail. The second reviews relations between municipalities and other levels of government elsewhere, including other provinces, the United States, Japan, Australia, France, and the United Kingdom. The report also reviews global trends affecting the role of municipalities in relation to other levels of government and the private sector. The experiences in the other jurisdictions and analyses of past Ontario reforms and global trends are then discussed in relation to Ontario's current disentanglement process.