Communalism usually refers to a system that integrates communal ownership and federations of highly localised independent communities. A prominent libertarian socialist, Murray Bookchin defines the Communalism (capital C) he developed as "a theory of government or a system of government in which independent communes participate in a federation", as well as "the principles and practice of communal ownership".
This usage of communalism appears to have emerged during the late 20th century to distinguish commune-based systems from other political movements and/or governments espousing (if not actually practicing) similar ideas. In particular, earlier communities and movements advocating such practices were often described as "anarchist", "socialist" and/or "communist".
Many historical communities practicing utopian socialism or anarchist communism did implement internal rules of communalist property ownership in the context of federated communalism. It is at least theoretically possible for a federation of communes to include communes which do not practice communalist rules of property, which is to say, that the overall national government may be a federation of communes, but that private property rather than communalist property is the order within each such commune. Karl Marx, often viewed as the founder of modern communism, criticized older forms, including primitive communism and/or utopian socialism, as poorly conceived and/or prone to disintegration in practise.
Communalism in the form described above is distinct from the predominant usage in South Asian forms of English: allegiance to a particular ethnic and/or religious group rather than to a broader society. As such, this usage is synonymous with sectarianism and associated with communal violence.