The Viscounty, later Principality of Béarn (Gascon: Bearn or Biarn), was a medieval lordship in the far south of France, part of the Duchy of Gascony from the late ninth century.

The citation of a certain "Gaston [son] of Centule, viscount of Béarn" (Gasto Centuli vicecomes Bearnensis) is the first attestation of a specific regional organization in the late 860s/early 870s.

While nominally part of the Duchy of Aquitaine, the Viscounts of Béarn frequently joined Aragonese military campaigns between the 10th and 12th centuries.

[5] Gaston VII, Viscount of Béarn, did homage to King Henry III of England as Duke of Aquitaine at Bordeaux in 1242.

In 1347, on the heels of English victory at the battle of Crécy (1346), the Viscount Gaston III Fébus paid homage to the king of France for his county of Foix, but stated that Béarn was to be held "from God and from no man in this world".

[9] Its chief seat and stronghold lay at Pau, a site fortified by the 11th century, and proclaimed as official capital of the independent principality in 1464.

[10] In 1564, Henry's daughter, Jeanne III, firmly opposing Rome, declared Catholicism outlawed and disbanded monasteries, confiscating church property.

[11] After Henry IV's death, Calvinists from Béarn attended the Huguenot conference at Saumur in 1611 in an effort to enlist their support for Béarnese and Navarrese independence.

In 1614, the same year he came of age, Henry IV's successor, Louis XIII, was confronted by a Huguenot uprising supported by Béarn.

In 1620, Louis marched into Béarn with a large army, convoked the estates and, sitting on his Béarnese throne, issued an edict of union with France, thus removing the principality's sovereignty.

[11] Louis preserved the freedom of worship of the Calvinists, the right of the estates to negotiate their taxes and the obligation of the king of France to swear to uphold the customary law of Béarn on his accession.