If the previous siege must be framed within the context of the Spanish-French conflicts, this one follows the same patterns but on a broader stage: the Thirty Years’ War. In 1636, Spanish troops reinforced by local militias invaded Labourd. In 1638, it was French troops that entered Guipúzcoa.
The fortress of Hondarribia was powerfully besieged in 1638 by a large French army commanded by the Prince of Condé, while the Archbishop of Bordeaux blockaded it by sea with a large fleet. The siege began on July 1 and lasted sixty-nine consecutive days. The garrison consisted of Irish soldiers, citizens of the town, and tercio troops from Tolosa and Azpeitia, sent by the province for its defense, totaling 700 men under the command of the Bilbaino Diego de Eguía.
The hardships of this long siege were severe. The enemy opened two breaches in the walls, making it possible to ride through them on horseback, blew up seven mines, and launched nine assaults, all repelled. Their bombs burned many houses. Despite this and the shortage of food, the town defended itself valiantly until September 7, when it was relieved by the Spanish army under Juan Alonso Henríquez de Cabrera, Admiral of Castile, who, after ascending Jaizkibel, attacked the French garrisons near the Virgin of Guadalupe hermitage, forcing them to flee to Hendaye.
The French suffered 1,500 killed, 2,000 captured, and 2,000 drowned while crossing the strait separating Fuenterrabía from Hendaye. The Spanish captured a rich booty in money, jewelry, clothing, important documents, all kinds of supplies, 20 pieces of artillery with their ammunition, and 54 flags.
A famous passage from a letter Domingo de Eguía sent to his wife summarizes the end of the siege:
"Friend: Since you know nothing of war, I will tell you that the enemy army divided into four parts: one fled, another we killed, another we captured, and another drowned. May God keep you; I am going to have dinner in Fuenterrabía."
According to chronicles, even a hundred armed women participated in the town’s defense. Philip IV, very pleased, sent a letter on September 15, 1638, expressing his royal appreciation and offering to rebuild destroyed houses and grant other favors.
In this royal letter, the king ed the town to propose which rewards were most suitable for the repair and recognition of its citizens. Their s included: repair of the fortress, payment for damages suffered during the siege, granting of rents, confirmation of privileges, establishment of markets and fairs, priority in tax levies, and protection of judicial and commercial rights. The king granted several of these s, including the title of very valiant city, the usufruct of Elgóibar’s parish church, military ranks for siege officers, and privileges for the townspeople and their descendants.
The siege of 1638, along with other sieges of Fuenterrabía, was frequently referenced in the Spanish Golden Age literature by Lope de Vega, Quevedo, Calderón, and others.