Thibaut Theobald (IV. Or VI) as count of Champagne, I. as king of Navarre, a French trouvere or poet, born at Troyes in 1201, died there or at Pamplona, July 10, 1253. He was a posthumous son of Count Thibaut III. or V., was educated at the court of Philip Augustus under the supervision of his mother, Blanche, daughter of Sancho the Wise, king of Navarre, and became an early adept of the "gay science." Several of his poems were addressed, under an assumed name, to Blanche of Castile, the queen of Louis VIII., whom he loved to distraction, although she was 14 years his senior. When her husband died prematurely at Montpensier in 1226, while returning from an expedition against the Albigenses, Thibaut, who accompanied him, was suspected of being his poisoner. He soon after joined the league of feudal lords who rose against Blanche, then regent; but her influence brought him back to his duty to the king, and through his assistance she baffled the designs of the confederates. In 1234 Sancho died without male issue, and the count of Champagne inherited the kingdom of Navarre in right of his mother. In 1239 he went to the Holy Land; but he met with a dreadful defeat near Gaza, and had to pay a heavy ransom for the release of his brother.

His provinces were very prosperous under his government, and he was a patron of literature and the fine arts. He allowed the Albigenses to be persecuted in his dominions, and assisted, May 13, 1239, in the burning at the stake of 83 of them, at Mon-trimer, near Vertus. Of his poems, 66 songs were published by Levesquo de la Ravalliere (2 vols. 12mo, Paris, 1742; best ed. by Rocque-fort and Michel, 1829). A collection of 81 songs is contained in Tarbe's Collection des poetes cliampenois (8vo, Rheims, 1851).