What is the REGALIAN DOCTRINE?
Under the Regalian doctrine or jura regalia, all lands of the public domain belong to the State, and the State is the source of any asserted right to ownership in land and charged with the conservation of such patrimony.19 Under this doctrine, lands not otherwise appearing to be clearly within private ownership are presumed to belong to the State.20
What is the remedy of the government if a public land is registered in the name of a private person?
In instances where a parcel of land considered to be inalienable land of the public domain is found under private ownership, the Government is allowed by law to file an action for reversion,21 which is an action where the ultimate relief sought is to revert the land to the government under the Regalian doctrine. Considering that the land subject of the action originated from a grant by the government, its cancellation is a matter between the grantor and the grantee