The small kingdom of Navarre lies on the frontiers between France and Spain; and as John d’Albert, the sovereign, was connected by friendship and alliance with Lewis, the opportunity seemed favorable to Ferdinand, while the English forces were conjoined with his own, and while all adherents to the council of Pisa lay under the sentence of excommunication, to put himself in possession of these dominions. No sooner, therefore, was Dorset landed in Guipiscoa, than the Spanish monarch declared his readiness to join him with his forces, to make with united arms an invasion of France, and to form the siege of Bayonne, which opened the way into Guienne:[*] but he remarked to the English general how dangerous it might prove to leave behind them the kingdom of Navarre, which, being in close alliance with France, could easily give admittance to the enemy, and cut off all communication between Spain and the combined armies. To provide against so dangerous an event, he required that John should stipulate a neutrality in the present war; and when that prince expressed his willingness to enter into any engagement for that purpose, he also required that security should be given for the strict observance of it. * Herbert, Holingshed, p. 813. John having likewise agreed to this condition, Ferdinand demanded that he should deliver into his hands six of the most considerable places of his dominions, together with his eldest son as a hostage. These were not terms to be proposed to a sovereign; and as the Spanish monarch expected a refusal, he gave immediate orders to the duke of Alva, his general, to make an invasion on Navarre, and to reduce that kingdom. Alva soon made himself master of all the smaller towns; and being ready to form the siege of Pampeluna, the capital, he summoned the marquis of Dorset to join him with the English army, and concert together all their operations.