The Latin legal term ''Ad Coelium'' was a concept applied to land ownership and jurisdiction. Translated to mean '' ''To The Sky'' – the principle meant meant that in addition to the actual parcel of land in question owned, the very ''sky above and ground below'' – was likewise under ownership as well. While no actual level of measurement was applied as to just how much of either was with regards to height and depth, ''Ad Coelium'' was seen as a means of total constructive control of a Region and all therein. Mostly used by Royalty in describing their Kingdoms, Ad Coelium was the predominant legal concept from the 9th thru 12th Centuries in most of Europe.