The death of Edward's beloved first wife, Eleanor of Castile, at the age of 49 in 1290, left him reeling in grief. However, it was much to Edward's benefit to make peace with France to free him to pursue his wars in Scotland. Additionally, with only one surviving son, Edward was anxious to protect the English throne with additional heirs. In summer of 1291, the English king had betrothed his son and heir, Edward, to Blanche of France in order to achieve peace with France. However, hearing of her renown beauty, Edward decided to have his son's bride for his own and sent emissaries to France. Philip agreed to give Blanche to Edward on the following conditions: A truce was concluded between the two countries. Edward gave up the province of Gascony. Edward agreed and sent his brother Edmund Crouchback, Earl of Lancaster, to fetch the new bride. Edward had been deceived, for Blanche was to be married to Rudolph III of Habsburg, the eldest son of King Albert I of Germany. Instead, Philip offered her younger sister Margaret to marry Edward (then 55). Upon hearing this, Edward declared war on France, refusing to marry Margaret. After five years, a truce was agreed upon under the influence of Pope Boniface VIII. A series of treaties in the first half of 1299 provided terms for a double marriage: Edward I would marry Margaret and his son would marry Isabella of France, Philip's youngest surviving child. Additionally, the English monarchy would regain the key city of Guienne and receive £15,000 owed to Margaret as well as the return of Eleanor of Castile's lands in Ponthieu and Montreuil as a dower first for Margaret, and then Isabella of France.