Definition of cuius est solum eius est usque ad coelum et ad inferos
Cuius est solum, eius est usque ad caelum et ad inferos (Latin for for whoever owns the soil, it is theirs up to Heaven and down to Hell) is a principle of property law which can be traced back to 1766, when William Blackstone boldly proclaimed the doctrine in his treatise Commentaries on the Laws of England. It was not a principle of Roman law, despite the Latin phrasing of the maxim, nor was the theory recognized in early common law. Rather, it is best viewed as hyperbole invented by Blackstone, without any prior foundation in English law. By the end of the 19th century, frequent repetition had transformed Blackstone's naked assertion into a supposed rule of American law.
As the name describes, the principle is that a person who owns a particular piece of land owns everything above and below it as well. Consequently, the owner could prosecute trespass against people who violated the border but never actually touched the soil. As with any other property rights, the owner can sell or lease it to others, or it may be taken or regulated by the state.
For example, suppose three people owned neighboring plots of land. The owners of the plots on the ends want to build a bridge over the center plot connecting their two properties. Even though the bridge would never touch the soil of the owner in the middle, the principle of cuius est solum would allow the middle owner to stop its construction or demand payment for the right to do so.
By the same principle, a person who wants to mine under somebody's land would have to get permission from the owner to do so, even if the mine entrance was on neighboring land.
The phrase was first coined by Accursius of Bologna in the 13th Century.
In Lord Bernstein of Leigh v Skyviews & General Ltd  QB 479, the Court noted that the phrase was 'colourful', but said that it was well settled in the common law that a land owner had rights in the air immediately above the land, extending in particular to signs overhanging from adjacent properties. The right did not extend though to more than was 'necessary for the ordinary use and enjoyment of the land and structures upon it'. Planes, hot air balloons, and the like, would not commit a tort of trespass by merely passing over a person's property.
The property right to air superincumbent to land was confirmed in Kelsen v. Imperial Tobacco Co.  2 QB 334, where a sign erected on a building that overhung the plaintiff's property committed the tort of trepass, even though no harm or nuisance was caused by it. An injunction was granted to the landowner causing the sign to be removed.
U.S. common law generally limits trespass claims to infringements a reasonable distance above and below the surface of the land.
- John G. Sprankling, Owning the Center of the Earth, 55 UCLA L. Rev. 979, 982-83 (2008).
- United States v. Causby, 328 U.S. 256 (1946)
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