Ralph I of Vermandois (French: Raoul Ier "le Vaillant") (1085 – 14 October 1152), Count of Vermandois. He was son of Hugh I, Count of Vermandois, and Adelaide, Countess of Vermandois and paternal grandson of Henry I of France and while his mother had been heiress to Herbert IV of Vermandois.
His only paternal uncle was Philip I of France. Through him Raoul was a first cousin of Louis VI of France and a first cousin, once removed of Louis VII of France.
Ralph served as the seneschal of France during the reign of his cousin Louis VII. Under pressure from Queen consort Eleanor of Aquitaine, Louis allowed him to repudiate his wife Eléonore of Blois in favor of Eleanor's sister, Petronilla of Aquitaine. This led to a war with Theobald II of Champagne, who was the brother of Ralph's first wife Eleonore. The war lasted two years (1142–44) and ended with the occupation of Champagne by the royal army.
Ralph and Petronilla were excommunicated by Pope Innocent II for their illegitimate marriage.
Ralph was married three times:
Preceded by Hugh I |
Count of Vermandois 1102–1152 |
Succeeded by Hugh II |