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.
Dorset began to suspect that the interests of his master were very little regarded in all these transactions; and having no orders to invade the kingdom of Navarre, or make war any where but in France, he refused to take any part in the enterprise.

He remained therefore in his quarters at Fontarabia; but so subtle was the contrivance of Ferdinand, that even while the English army lay in that situation, it was almost equally serviceable to his purpose, as if it had acted in conjunction with his own.

It kept the French army in awe, and prevented it from advancing to succor the kingdom of Navarre; so that Alva, having full leisure to conduct the siege, made himself master of Pampeluna, and obliged John to seek for shelter in France.