While the Spanish army was preparing to attack Navarra, Marshal Pedro of the Navarro army and Beaumoniano Mauleko Ladron began contacts to try to avoid the invasion. However, in vain, the intentions of the Castilian king were firm, imposing increasingly unacceptable conditions that the Navarros kings denied and justified the conquest. At the same time, the competition valve of the kings of Navarre was being negotiated with the Vatican to legitimize the invasion, but this came in full conquest.