[6][7] In St. Catherine’s Milling and Lumber Co. v. The Queen (1888), the Supreme Court initially described aboriginal title as a “personal and usufructuary right” which derives its source from the Royal Proclamation of 1763.
[9][10] While the Royal Proclamation recognized the existence of aboriginal title, the constitutional document issued by King George III is not its source.
It is now clear in Canadian constitutional law that the doctrine of terra nullius (roughly, "no man's land") never applied in Canada.
Instead, the Royal Proclamation expressly recognizes that aboriginal peoples were in possession of the land prior to assertion of British sovereignty.
In Guerin v The Queen (1984), the Supreme Court described aboriginal title as a right that derives from indigenous people's historic occupation and possession of their traditional lands.
As Justice Gérard Vincent La Forest put it in Delgamuukw v. British Columbia, Aboriginal title “is not equated with fee simple ownership; nor can it be described with reference to traditional property law concepts".