Rudolf or Rudolph (French: Raoul de Genève) was the Count of Geneva from 1252 until his death in 1265. He was the eldest son of William II, and was described by a Renaissance historian as “the more quarrelsome son of a quarrelsome father.” He was a constant warrior, and his most frequent foes were of the House of Savoy.
Around 1234 Aymon II of Faucigny made himself protector of the priory of Chamonix, in violation of the rights of the Count of Geneva, then William II. This precipitated a war between the house of Geneva and that of Faucigny allied with the house of Savoy in the person of Aymon's son-in-law Peter, “the Little Charlemagne”. Late in 1236 or early the next year, during a temporary truce, Rudolf ambushed Peter in a mountain pass, while the latter was travelling with a very small retinue, and made him a prisoner. The exact circumstances of the ambush and of the events which followed are obscured, but it appears that in the ensuing war the Genevans were beat. On 13 May 1237 Peter's elder brother, Amadeus IV of Savoy, acting as arbiter of the dispute between Geneva and Faucigny, ordered William II to pay an war indemnity and hand over certain fortresses. In the end Peter was freed.
In 1250, when the Savoyards appeared to be engaged in a concerted effort to expand their territory, William II and Rudolf again went to war, this time mainly in defence of the Albert III of La Tour-du-Pin, who was William's brother-in-law and Rudolf's father-in-law, and whose lands were threatened by both Peter and his brother Philip. In the war Savoy defeated Geneva, and Philip imposed a “Carthaginian peace” on the losers. The indemnity had never been paid and was mercifully halved, and more castles were taken. It was a reduced patrimony that Rudolf inherited two years later.
In November 1252 William II died at Domène. Rudolf immediately acted to expand his shrunken county of Geneva. By arms he forced Simon de Joinville, the lord of Gex, to do him homage. He seized the castle at Charousse and expelled a creditor of “the Little Charlemagne”, who was holding it as security on a loan. For this castle he steadfastly refused to do homage to any Savoyard. When his aunt, Margaret, the dowager countess of Savoy, died in 1258, Rudolf took over the lands at Cornillon and the Val des Clefs that formed her dowry.