On October 20, 1620, by the Edict of Pau, King Louis II of Navarre and XIII of France formally oversaw the unification of his two crowns, thereby bringing to a close the full sovereignty of the whole of Navarre, a kingdom that had existed independently since 824. From this moment on, the ruling monarch would be known as the King of France and Navarre.
By the terms of the Edict of Pau, the Navarrese territories of Lower Navarre (Nafarroa Beherea), Béarn (Biarn in Gascon), and the Donezan (Donasan in Occitan) passed into the hands of the French crown, while another possession, Andorra, would henceforth be ruled jointly as a co-principality. These were all lands with their own highly developed systems of self-government.
By the terms of the Edict, moreover, the Sovereign Council of Béarn was transformed into the Parliament of Pau with jurisdiction over Lower Navarre in the Basque Country (whose own governing authority, the Chancellery of Donapaleu /Saint-Palais, was incorporated into the new parliament). One consequence of this decision was that Basque, which had been used in official circles to that date in conjunction with the other official languages of the Kingdom of Navarre, would be replaced by French as the one official language of the public administration. Moreover, an additional provision of the Edict was that the easternmost Basque province of Zuberoa would now come under the jurisdiction of the Parliament of Bordeaux, thereby separating and differentiating it from its neighbor Lower Navarre.
In one final, and slightly ironic move (in light of the changes that had taken place), by a further edict of 1624, the Parliament of Pau was renamed the Parliament of Navarre, while retaining its location in Pau, Béarn.