The Siege of Boulogne (19 July-18 September 1544) occurred during King Henry VIII of England's campaign in France at the time of the Italian War of 1542-46. An English army under the command of King Henry VIII and the Duke of Suffolk laid siege to the French Channel port of Boulogne for two months, capturing it after undermining its walls. However, the English army suffered heavy losses, losing around half of its men from disease.
King Henry VIII was motivated to take Boulogne after the German ambassador Eustace Chapuys informed King Henry that Emperor Charles V was offering to allow for Henry to reclaim Aquitaine (lost during the Hundred Years' War) from France in return for Henry joining the Holy Roman Empire's war with King Francis. Henry agreed, and he raised 40,000 troops to invade France.
Start of the siege
King Henry entrusted Thomas Seymour with command of the English fleet, while the Duke of Suffolk commanded the army. King Henry himself would accompany his soldiers, and he named Queen Catherine Parr as regent. The French retreated behind the walls of Boulogne, which they believe to be impregnable; however, King Henry had his cannon be deployed, and they inflicted devastating damage on the walls. King Henry proceeded to have engineer Girolamo da Treviso mine underneath the walls within two weeks, hoping to destroy the castle from underneath. The French broke out just beyond the southern gate, so King Henry sent Suffolk to guard all of the gates as Earl of Surrey repelled the advance. The two English nobles joined forces and repelled the attack, and Suffolk captured a French woman, Brigitte Rousselot, who had taken part in the attack.
Soon, the "bloody flux" (dysentery) broke out in the English camp, spreading to soldiers throughout the army. This outbreak was partially caused by French prostitutes entering the camp and having sex with the soldiers. More than 2,000 men died of disease and starvation tunneling their way into the castle, and a further 3,000 were too sick to fight. King Henry refused to take ships away from his blockade to take the plagued men back to camp, instead ordering for his chief surgeon to take the men out of their sickbeds and have them fight; he said that the men were sick from cowardice, not disease. Disease was only one of the troubles faced by soldiers, however; both the defenders and the besiegers suffered from starvation. The countryside around the city was barren, and French peasants begged English soldiers for loaves of bread to feed their dying infants. However, Earl Suffolk was not concerned about the French, but about his own men; he was frustrated that the French would not break lances with the English as they used to. While his siege stalled, King Henry and his generals dined lavishly, eating fruits, meats, and having waiter service; meanwhile, the soldiers either starved or had to share their rations with each other.
End of the siege
The King's engineer Treviso saved the siege by exploding a mine that spectacularly brought down the city's walls, leaving Boulogne defenseless. Treviso heroically died in the process, and the destruction of the city's walls allowed for the English to assault the city itself. Governor Jacques de Coucy arrived at the English camp with the keys to the city, and King Henry gave his promise to allow for its citizens and unarmed combatants to safely evacuate the city.
The English had won a victory over the French, but at great cost: half of the English army had been lost to disease or battle. Henry was unable to go ahead with his planned march on Paris, and he received further bad news: Holy Roman Emperor Charles V concluded a separate treaty with the French after his siege of Luxembourg dragged on for too long. Soon, the Dauphin of France gathered 36,000 troops and prepared to retake Boulogne, leading to King Henry ordering for the Earl of Surrey to hold the city. Nevertheless, King Henry wanted his victory celebrated in every house, for Thanksgiving masses to be held, and for "Boulogne" to be imprinted on every herald, like Agincourt.
Further fighting for Boulogne
In 1545, the Earl of Surrey would rashly attack a large convoy of French supply forces at Saint-Etienne, just beyond Boulogne, costing him 600 troops (including all of the captains and gentlemen of his army, whom he placed on the front line). King Henry announced this to his Privy Council, and he commanded for the Earl of Surrey to return to England and be examined by his court for disobeying his orders to not act boldly and endanger Boulogne. The King appointed Lord Hertford as his replacement as garrison commander. The Earl of Surrey would have his rank withdrawn, and he was later executed for treason.
Meanwhile, a large French fleet was fitted for war, while Emperor Charles V ordered all English ships and properties in the Low Countries to be seized. The French ambassador to England, Charles de Marillac, later talked to Lord Hertford and attempted to convince him to persuade the King of his folly in attacking Boulogne against all reason; Hertford had opposed the war, which bankrupted England. In January 1547, he was forced to surrender his prized Boulogne to France as part of a peace treaty.