Peter I of Courtenay
Peter I of Courtenay (c. 1126–1183) was the sixth son of King Louis VI and Adelaide of Maurienne. He joined his brother Louis VII on the Second Crusade in 1147, and was the only brother to stay loyal during the revolt of 1149–1150.
Around 1150 he married Elizabeth de Courtenay, heiress to the lordships of Courtenay and Montargis, founding the Capetian House of Courtenay. He took the cross again in 1179, died in the Holy Land, and left a son who became Latin Emperor of Constantinople.