What is Petition De Droit?

Legal Definition
L. Fr. In English practice. A petition of right; a form of proceeding to obtain restitution from the crown of either real or personal property, being of use where the crown is in possession of any hereditaments or chattels, and the petitioner suggests such a right as controverts the title of the crown, grounded on facts disclosed in the petition itself. 3 Bl. Comm. 256.
-- Black's Law Dictionary
Legal Definition
A petition of right, by which property in the possession of the crown is recovered in chancery.
-- Ballentine's Law Dictionary