G randson, by his mother, of the count of Toulouse Alfonse Jourdain, Bernard succeeds his father Dodon as count of Comminges in 1176. Perfect illustration of the brave and passionate Southern knight, it is also a quite diplomatic flexibility. Having taken a stand, carefully, with the king of Aragon in the conflict which sets him in Raimond V of Toulouse, it tries to put the hand on Bigorre by marrying the girl of the count Centulle III; but this marriage does not last and Bernard IV is engaged in a policy of seesaw between Toulouse and Aragon. In 1197, he marries Marie of Montpelier following an operation of high diplomacy with Raimond VI and Pierre II of Aragon. Already Vassal of the first for Low wall and Samatan, he becomes second'one for the rest of the lands; in exchange for this honoring, Pierre II gives him the Valley of Aran. Soonly Bernard IV rejects Marie of Montpelier who marries Pierre II immediately! To advise of Raimond VI, it has an active part in the release of hostilities against the crusaders, in 1211 , that is worth him the occupation of his county by Montfort ( 1212 ) .He participates in the battle of Low wall but saves its head by submission to the pope, on April 18, 1214. Taken refuge in Luchonnais, he pushes Raimond VI to enter into Toulouse and becomes the soul of the defense against Montfort. Becoming again the chief of the county after the defeat of the crusade, he lives in Toulouse, assists Raimond VI in his last moments and advises Raimond VII. In 1223, he goes in pilgrimage to Compostelle then, in May, 1224, marry his son Bernard to Cécile de Foix. Fallen ill, he dies on February 22, 1225.