In England and perhaps other common law jurisdictions, property ownership is governed by the feudal remnant called "tenure", whereby what is commonly called "owning" is actually a "freehold" / "fee simple". This maintains a fiction (?) that the monarch is the real "owner" who just grants the practical owner extensive rights. Quoting from the latter link:
The rights of the fee-simple owner are limited by government powers of taxation, compulsory purchase, police power, and escheat, and may also be limited further by certain encumbrances or conditions in the deed, such as, for example, a condition that required the land to be used as a public park, with a reversion interest in the grantor if the condition fails; this is a fee simple conditional.
In English common law, the Crown had radical title or the allodium of all land in England, meaning that it was the ultimate "owner" of all land in the past feudal era. Allodial title is reserved to governments under a civil law structure.
However, the Crown can grant ownership in an abstract entity – called an estate in land – which is what is owned rather than the land it represents. The fee simple estate is also called "estate in fee simple" or "fee-simple title", or sometimes simply "freehold" in England and Wales. [...]
William Blackstone defined fee simple as the estate in land that a person has when the lands are given to him and his heirs absolutely, without any end or limit put to his estate. Land held in fee simple can be conveyed to whomsoever its owner pleases; it can also be mortgaged or put up as security. Owners of real property in fee simple have the privilege of interest in the property during their lifetime and typically have a say in determining who gets to own an interest in the property after their death.
All this seems like a lot of legal acrobatics to not technically abolish the monarch's feudal rights. I assume that such concerns hold no weight in republics who have cleanly broken with the monarchical legal systems.
So:
- What is the legal basis for land ownership in countries which do not follow this post-feudal pattern?
- Instead of claiming a higher right to the property via these feudal means, on what do such jurisdictions base the use of powers of "taxation, compulsory purchase, police power, and escheat"? Is it simply by law?