Sieges of Boulogne ( 1544 – 1546 ) There were two sieges of Boulogne , in the Pas - de - Calais , during the Italian War of 1542 – 1546 . Boulogne was fortified and defended as an English possession on the French mainland between 14 September 1544 and March 1550 . First siege . The Siege of Boulogne took place between 19 July and 18 September 1544 , during the third invasion of France by King Henry VIII of England . Henry was motivated to take Boulogne by the French giving aid to England ' s enemies in Scotland . In 1543 he made a new alliance with Charles V , Holy Roman Emperor and King of Spain , whose Roman Catholic allegiances were , for a time , overruled by the political advantages of an alliance with England against France . In early 1544 , a large English force departed from the Pale of Calais . Later , this split into two parts , and one of them , under the Duke of Suffolk , marched to the coastal town of Boulogne and laid siege to it on 19 July . A few weeks later , Henry arrived to take command of the siege himself . The lower section of the town , fortified lightly , fell quickly to heavy bombardment , which continued through August . By September , the upper town was breached and taken , but the central castle still held out . The French garrison ' s firepower prevented any approach on foot , so the English dug tunnels under the castle , and the French surrendered on 13 September . However , the Emperor Charles V then made a separate peace with France , and the French attacked Boulogne in the Second Siege of Boulogne . Over the following years , neither England nor France found the strength to engage in full - out war with one another . French attempts to retake Boulogne failed , while English attempts to gain more territory around Calais and Boulogne also failed . Henry awaited a large French invasion fleet which never came , and subsequently much of England ' s military resources during his and his son ' s reigns were diverted to the war in Scotland . Second siege . The Second Siege of Boulogne was an engagement late in the Italian War of 1542 - 1546 . The Dauphin ' s army descended on Montreuil , forcing the Duke of Norfolk to raise the siege ; Henry VIII himself left for England at the end of September 1544 , ordering the Dukes of Norfolk and Suffolk to defend Boulogne . The two Dukes quickly proceeded to disobey this order : leaving some 4 , 000 men to defend the captured city , they withdrew the rest of the English army to Calais . The English army , outnumbered , was now trapped in Calais ; the Dauphin , left unopposed , concentrated his efforts on investing Boulogne . On 9 October , a French assault nearly captured the city , but was beaten back when the troops prematurely turned to looting . The English armoury and the conclusion of the siege in 1550 . Fortifications . After Henry VIII ' s personal visit to Boulogne on 18 September the English began fortifying their position . Boulogne had a high and low town , and the citadel of Boulogne was in the low town adjacent to the harbour near the mouth of the river Liane . To the north a roman lighthouse called the ' Old Man ' was fortified , and a new fort built between the Old Man and Boulogne in 1545 was called the ' Young Man . ' The surveyor of these works was John Rogers who had been a master mason . The military engineer Richard Lee and Thomas Palmer , treasurer of Guînes , brought additional instructions directly from Henry VIII . Another outlying fort was built on a hill to east from May 1546 . Now called Mont Lambert , it was then called Boulemberg . However , Nicolas Arnold , the captain of Boulogne complained of its shortcomings ; it held no well , or room for storage . It was abandoned in 1549 on the approach of a French army . The French fortified south of the Liane , building the Fort de Châtillon and Fort d ' Outreau . The building of any new fortifications was supposed to have ceased under the Treaty of Camp ( or Treaty of Ardres ) made in June 1546 . The treaty provided that the English would evacuate Boulogne in 1554 in return for 2 , 000 , 000 crowns . The English possession of Boulogne was eventually compromised by the French construction of a fort at Marquise , north of the town , which could blockade supplies . Although records are incomplete , it is clear that large numbers of English labourers died or became sick during the works . Of 1 , 200 men sent in January 1545 , only 300 were still working in June . Armoury . The guns of Boulogne were listed in the inventory of English crown possessions taken after Henry VIII ' s death on 28 January 1547 . Most of their wheels and stocks were said to be rotten and decayed . The totals were ; 4 cannons ; 5 demi - cannons ; 10 culverin s ; 14 demi - culverins ; 18 sakers ; 21 falcons , falconets , and chamber falcons ; 25 great brass mortars ; 19 small brass mortars ; 9 iron mortars ; 3 iron bombards ; 3 iron cannon - perrier ; 16 port - pieces ; 24 fowlers ; 7 slings ; 12 double bases ; 54 shrimp bases ; 114 privy bases ; 2 robinets ; and 73 brass hagbuts . The guns were in four positions ; the Old Man ; High Boulogne ; Base Boulogne ; and the Boulemberg ( Mont Lambert ) . When Boulogne was returned to France in March 1550 , Edward VI noted that the guns too would be handed over . These included recently captured pieces and ; 2 basilisks ; 2 demi - cannon ; 3 culverins ; 2 demi - culverins ; 3 sakers ; 16 falcons ; 94 arquebus a croc with wooden tails ( muskets for fixed positions ) ; and 21 iron guns . Continuing conflict . There was a truce between the French and English at Boulogne according to a treaty made between Edward VI of England and Francis I of France in March 1547 . In June 1547 , an international dispute arose over a wall the English were building at the harbour . The French claimed it was a new fortification in breach of truce under the Treaty of Camp , while the English maintained that it was merely a sea wall to protect the haven . In the diplomacy , this dispute was connected with arguments over English and French intentions and intervention at St Andrews Castle in Scotland . In the summer of 1548 , the French observed the mole was provided with a flanker and cannon ; the English insisted it was merely to protect the workmen . French ships fired at it and the English returned fire . Edward Seymour , 1st Duke of Somerset told François van der Delft that the French were constructing forts at Boulogne in contravention of treaty in September 1548 ; in December the French managed to destroy two new outposts the English were building , and another fort nearer to Guînes and Calais called Fort Fiennes . A major attempt on Boulogne by the French was repulsed in May 1549 . The Imperial ambassador , Simon Renard , reported a failed assault on the fort at Boulemberg , or Mount Lambert . The French leader , Gaspard II de Coligny , sieur de Châtillon , a nephew of the Constable of France , set ladders against the fort at 2 : 00am but the alarm was sounded by members of the garrison who he believed he had successfully bribed . 200 French were killed . The English suspected treachery as four guns blew up on their first firing and around seventy men were absent without leave . The womenfolk in the fort were said to have saved the day . Some laughed at Châtillon , saying he had made his scaling ladders too short , although the action was well - conceived as the fort was crucial to the defence of the town . Moreover , the action was said to be in breach of treaty . Edward VI recorded this night assault in his chronicle , with a failed attempt to burn the ships in the harbour . In the summer , Coligny bombarded the pier with a battery of 20 , 000 shot , and blockaded the mouth of the haven with artillery . The English overran this artillery position and the French set up another which was less commanding . An attempt to foul the harbour with a hulk laden with stones also failed to incovenience the English garrison . English withdrawal . Although by the Treaty of Camp , the English had agreed to evacuate Boulogne in 1554 , the town was returned to France in 1550 under the Treaty of Boulogne which also concluded the war of Rough Wooing in Scotland . Simon Renard reported that the English captain accepted his order to surrender from the Privy Council with a sigh . Henry II of France formally entered the town on 16 May 1550 . He stayed three days and visited the forts of the Boulemberg , Ambleteuse , the Tower of Ardres , the Great Fort and Fort Châtillon ( also called Châtillon ' s garden ) . He was impressed with some of these recent fortification works and also with the English scheme for bringing freshwater to the town . Henri II determined to continue building the English star fort at Ambleteuse and the neighbouring work at Blackness . The French also admired the mole , which they called ' la Dunette , ' and when completed Henri II compared it to a Roman work . The Basilica of Notre - Dame de Boulogne , destroyed or badly damaged by the English , was to be rebuilt , Henri II gave the church a silver statue of Our Lady , and other nobles subscribed money . In popular media . The First Siege of Boulogne was depicted in the 4th season of the television series " The Tudors " .