In modern law, this principle is still accepted in limited form, and the rights are divided into air rights above and subsurface rights below. Property title includes to the space immediately above and below the ground – preventing overhanging parts of neighboring buildings – but do not have rights to control flights far above the ground or in space. In dense urban areas, air rights may be transferable (see transferable development rights) to allow construction of new buildings over existing buildings.
Early versions of the maxim have been traced to the 13th-century Italian jurist Accursius, and is said to date in common law to the time of Edward I. It was more recently promulgated, in broad form (air above and ground below) by William Blackstone in his influential treatise Commentaries on the Laws of England (1766).
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 is credited to the glossator Accursius in the 13th Century. It has been suggested that the principle was brought to England by Accursius's son, Franciscus Accursius, who came to England with Edward I on the latter's return from the crusades. The principle was firmly established in common law by Edward Coke in Bury v. Pope (1587), which gives the first statement in English law of the principle, writing (Liber 1, section 1, page 4, section "Terra" (earth)):