Land tenure

Land tenure is the term for the legal system and/or systems in place that govern individuals' use of real property. Throughout most of history and into the present, individuals did not actually "own" the land where they lived and/or worked. Instead, the land is owned by the government and the population merely held one of various types of leases. Land tenure laws are the bane of libertarians, Freeman on the land, and tax protestors of all stripes. The system where individuals actually own the land, free of all restrictions, is called allodial title and exists virtually nowhere except in a few jurisdictions in pre-revolutionary France and in limited situations in Nevada and Texas. Eminent domain is only possible because of this lack of allodial title. In common law countries (most of the anglosphere excepting Louisiana) land tenure laws are one of the last remaining bastions of feudalism.

History
Beginning with the feudal era, all land was owned by the sovereign. The sovereign would then grant the use of that land to various subjects, who would then parcel out the use of that land, and so on. Because of the way common law systems work, no law really ever "goes away" and the government of most common law countries is still the only true "owner" of the land. This is the basis for property taxes, which are in reality a form of rent paid for the use of the sovereign's land. Civil law countries operate much the same way, reserving allodial title for the government itself but under less feudal conditions. In the modern age, constitutional law places limits on the sovereign and/or government's ability to mess with tenants, but the basic principal of government ownership of all land within that government's jurisdiction remains the same.

Sharecropping
Sharecropping was a popular system of land tenure implemented in the United States during the period immediately following the American Civil War. This entails the "owner" of a property granting the right to farm a portion of that land to somebody else (in the U.S. context, usually newly freed former slaves) in exchange for a percentage of the crop yield. This allowed former slave-owners to continue to exploit their workers without having to actually do any work themselves.

Usufruct
Usufruct is the civil law equivalent to land tenure. When you purchase real property in a civil law country, what you are really getting is usufruct, that is, the exclusive rights to use the property and anything that the property produces, along with the right to sell this. Usufruct is common in systems where land is owned communally, rather than by a central government.

Libertarians and such
Libertarians and tax protestors who argue that the government has no right to tell them what to do are ignoring the essential truth that by law all residents of any given country are really just tenants with a landlord wealthy enough to field their own military. Whether or not this is a desirable state of affairs is a different matter entirely.