On December 19, 1308, at Alcalá de Henares, King Ferdinand IV of Castile and the ambassadors from the Kingdom of Aragon, Bernaldo de Sarriá and Gonzalo García agreed to the terms of the Treaty of Alcalá de Henares. Ferdinand IV, supported by his brother, Pedro de Castilla y Molina, the archbishop of Toledo, the bishop of Zamora, and Diego Lopez V de Haro agreed to initiate a war against the Kingdom of Granada on June 24, 1309. It was agreed that the Aragonese monarch could not sign a separate peace accord with the Emir of Granada. A combined Aragonese-Castilian navy was also formed to support the siege in a blockade of the coastal Granadian towns. It was further agreed that the Kingdom of Castile would attack the towns of Algeciras and Gibraltar and that the Aragonese forces would conquer