Blanche of Navarre, Countess of Champagne

Blanche of Navarre (c. 1177–1229), daughter of King Sancho VI and Sancha of Castile, married Count Theobald III of Champagne in 1199. Widowed in 1201 while pregnant, she bore Theobald IV days later and ruled Champagne as regent until 1222. She at once paid homage to Philip II at Sens, the first countess to do so, securing her son's rights.

In 1212 she established procedures allowing daughters to inherit castles without a son. In 1215 Philippa of Champagne and Erard of Brienne-Ramerupt made war on her claim; backed by Pope Innocent III, Blanche forced them to renounce it by 1222. She died in 1229.