John IV was a Count of Armagnac, Fézensac, and Rodez from 1418 to 1450.
Background
He was the son of Bernard VII of Armagnac, Count d" Armagnac, of Fézensac, Pardiac, and Rodez. And Bonne of Berry. His father had taken the County of Comminges by force, but John IV could not prevent the second marriage of Marguerite to Mathieu de Foix in 1419.
Career
Subsequently they took the County of Comminges. In 1425, he recognized the King of Castile as overlord of Armagnac. The French king, occupied fighting the English, could not intervene, but did not overlook the affront.
In 1440, he took part in a revolt of the barons and the Dauphin of France, but the coalition was overcome by Charles VII, who pardoned the insurrectionists.
He asked the Count of Armagnac to give up its kingly formula, but this last was refused. Charles VII then asked the Dauphin to punish the recalcitrant John IV. Besieged in L"Isle-Jourdain, John IV was made prisoner and imprisoned in Carcassonne in 1443.
He was pardoned three years later, but his counties were directed by royal officers, and he did not have any more noble capacities until his death.