Siege of Luxembourg ( 1794 – 95 ) The siege of Luxembourg was a siege by France of the Habsburg - held Fortress of Luxembourg that lasted from 1794 until 7 June 1795 , during the French Revolutionary Wars . Although the French army failed to breach the walls of the city , which were renowned as amongst the best in the world , the fortress was forced to surrender after more than seven months . Luxembourg ' s long defence led Lazare Carnot to call Luxembourg " the best [ fortress ] in the world , except Gibraltar " , giving rise to the city ' s nickname ' the Gibraltar of the North ' . The result of the capture of Luxembourg was the annexation of the Southern Netherlands into France on 1 October 1795 . Most of Luxembourg ( including all of the modern Grand Duchy ) , became a part of the département of Forêts , which was created on 24 October 1795 . Background . After taking Rheinfels Castle , the French were masters of the left bank of the Rhine , with the exception of the fortresses of Mainz and Luxembourg . The Committee of Public Safety therefore ordered that both of these should be conquered . The Army of the Rhine , commanded by General Michaud , attacked Mainz , while the Army of the Moselle under Jean René Moreaux would deal with Luxembourg . The French were particularly eager to take this city as they were hoping to find large stocks of provisions and war materials , which they were lacking . Field Marshal Baron von Bender was the governor of Luxembourg , and the commander of the city was Field Marshal - Lieutenant von Schröder . 15 , 000 were garrisoned in the city , which was also defended by 500 guns , cannons , mortars and howitzers . Prelude . On 19 November 1794 , the two companies of the 5th dragoon regiment which made up the vanguard of the division of General Jean - Baptiste Debrun were met around Liège by a large Austrian contingent of 1 , 500 infantrymen and 400 cavalry , which they defeated despite their numerical inferiority . On 21 November , on the edge of the forest of Grünewald , the Debrun division encountered an Austrian outpost of 400 infantrymen , 300 Hussar s and 6 artillery pieces . The brigade of General Péduchel pursued the enemy up to the reach of the cannons of Luxembourg . The confrontation , started at 11 : 30 , lasted until nightfall , and ended in a victory for the French , who captured 4 cannons and their caissons . Siege . The commander - in - chief , Moreaux , arrived on 22 November and deployed his three divisions around the city . The Tapronnie division occupied the road to Trier ; the Debrun division took the road to Arlon ; the third was on the road to Thionville ; the reserve was in Frisange . The artillery of the city engaged in intense firing on anything that was within range . The soldiers of the Army of the Moselle suffered from the hardships of winter , and lacked supplies . Often , half the men were not at their posts , but were buy pillaging the neighbouring villages to find food . General Moreaux , in late January , requested Field Marshal Bender to surrender honourably , but this was declined . Unable to allow themselve to pillage like their soldiers , the officers also suffered from hunger . Moreaux fell ill and had to be evacuated to Thionville , where he died in the night of 10 to February . Command was now in the hands of General Jean - Jacques Ambert , but the Committee of Public Safety , in order to put an end to the siege of Mainz , decided to send the three divisions of the Army of the Moselle and its new commander to reinforce the Army of the Rhine . The Army of the Moselle ' s place would be taken by two divisions of the Army of Sambre - et - Meuse under Generals Chapsal and Desjardins . The artillery was entrusted to Major General Bollemont , while Jacques Maurice Hatry became Commander - in - Chief . The two armies crossed on 20 March . Witnessing these movements , those inside the city thought that the French were lifting the siege , and engaged in several sorties to harass them , but were repulsed . In the last days of April , General Hatry renewed the offer for the city to surrender , but this was declined again . He then started constructing a shielded battery on a nearby height , equipped with mortars , in order to bombard the city . Faced with this threat , the Austrians attempted a massive sorty on the night of 15 to 16 May , but were repulsed with heavy losses . Newly convinced of the futility of such actions , the governor ordered the continual bombardment of the French artillery positions . The firing lasted 12 days , but the French batteries retaliated and caused numerous casuaties , to the extent that the residents asked Bender to capitulate . On 1 June , an envoy was sent to General Hatry , and on 7 June , the capitulation was signed at the French headquarters in Itzig . On 12 June , the 12 , 396 men still making up the garrison , left with the honours of war in front of 11 , 000 French soldiers . The last Austrian column was mostly composed of Belgian and Walloon soldiers , who laid down their arms , refused to follow the Austrians , and asked to serve France . The French made a triumphal entry into the city : their first act was to plant a " tree of liberty " on the Place d ' Armes . Consequences . As they had hoped , the French captured a large amount of war material : 819 cannons , 16 , 244 firearms , 4 , 500 sabre s , 336 , 857 cannonballs , 47 , 801 bombs , 114 , 704 grenades , and 1 , 033 , 153 pounds of powder . The capture of the Fortress of Luxembourg allowed the French Republic ' s annexation of the Southern Low Countries . On 1 October 1795 , most of Luxembourg became part of the Département des Forêts , created on 24 October 1795 . Only the left bank of the Rhine , Mainz , now remained . References . city