Battle of San Marino The Battle of San Marino was an engagement on 17 – 20 September 1944 during the Italian Campaign of the Second World War , in which German Army forces occupied the neutral Republic of San Marino , and were then attacked by Allied forces . It is sometimes known as the Battle of Monte Pulito . San Marino had declared its neutrality earlier in the war , and had remained broadly unaffected by events in Europe until 1944 , when Allied forces had advanced a sizable distance up the Italian Peninsula . A major German defensive position , the Gothic Line , ran across the peninsula a short distance south of the Sanmarinese border , and in late June , the country was bombed by the Royal Air Force , killing 35 people , in the belief that the German army had taken up positions on its territory . In Operation Olive , launched in late August , a strong Allied force attacked at the very eastern end of the line , aiming to pass through Rimini — just east of San Marino — and break out onto the plains north of the city . Whilst San Marino was southwest of Rimini , the plan was for it to be bypassed entirely . In response to the Allied movements , the Germans sent a small force into San Marino to guard their lines of communication and act as artillery observers . After a few days , the main thrust of the offensive was halted south of Rimini by strong resistance and severe weather , and the British and Indian flanking forces began to push westwards , taking the frontline towards San Marino . On 17 September the 4th Indian Division attacked forces of the 278 . " Infanterie - Division " holding two hills just across the Sanmarinese border ; after heavy fighting to gain control of the hills , the situation stabilised on the 19th , and Allied forces began to push into the city of San Marino itself . The city was captured by the afternoon of 20 September , and the 4th Indian Division left the country on the 21st , leaving it under the control of the local defence forces . Background . The small microstate of San Marino — in the northern Italian peninsula and fully surrounded by Italy , had played little role throughout the Second World War . It had a fascist government , closely aligned with Benito Mussolini ' s regime , but remained neutral . It was reported to have declared war against the United Kingdom in September 1940 , though the Sanmarinese government later transmitted a message to the British government stating that it had not . In early 1942 , the Sanmarinese government reiterated it was not at war with the United States , a position that was confirmed by the US State Department . The British Foreign Office noted more equivocally in 1944 that Britain had never declared war , but also had never formally recognised San Marino ' s neutrality , and that it felt that military action on Sanmarinese territory would be justified if it were being used by Axis forces . The country was bombed by the Allies on 27 June 1944 , killing at least 35 . The Sanmarinese government declared the same day that no military installations or equipment were located on its territory , and that no belligerent forces had been allowed to enter . In early July , it announced that prominent signs had been put up at the border crossings by the German command , to instruct German units not to enter the territory , and again reiterated its complete neutrality . Prelude . Assault on the Gothic Line . By the late summer of 1944 , German forces in Italy had withdrawn toward the Gothic Line , a chain of defended positions stretching across the Italian peninsula . The Allies formulated a plan to break through the defences , pushing north toward Rimini and the plains of Northern Italy . This would involve a strong thrust up the eastern seaboard by the British Eighth Army , codenamed Operation Olive ; 11 divisions would attack along a narrow front , converging on the " Rimini Gap " , an stretch of plain along the coast around the city , and then moving northward . Once through the Gap , the force would deploy outward onto the Romagna Plain , and move westward toward Bologna . Meanwhile , the American Fifth Army would push north along the centre of the peninsula , hopefully converging on Bologna and trapping a large German force in a pincer movement . The main Allied assault began on 25 August , reaching the Foglia valley — the Gothic Line proper — on 29 August . It was quickly breached , and the German command attempted to assemble a second defensive line on the Coriano ridge , a hilly spur to the north of the Conca river , and the last major geographic obstacle south of Rimini . The Allied offensive reached the river on 3 September , but ground to a halt due to mechanical difficulties with its tanks , strengthening German resistance , and heavy rain . The Allied forces halted , and brought up reinforcements whilst waiting for a chance to resume the offensive along the coast . On the left flank of the assault , the attack had been halted in the Battle of Gemmano , to the south of the Conca river . At this point , the forces on the Allied left wing were strung out in a line running due south from the Coriano ridge , facing westward toward San Marino , a few miles distant . The 56th Division was opposite Croce , with the 46th Division opposite the heavily defended position at Gemmano . The 4th Indian Division was to the south of the 46th , forming the very left wing of the offensive . When the assault on Coriano was resumed on the 12th , led by two armoured divisions with heavy artillery support , these forces pushed westwards ; their goal was to pass through towards the town of Montescudo , about two miles from the Sanmarinese border . The main assault successfully pushed onto the ridge , and the 56th Division advanced about past Croce , before digging in on the evening of the 13th ; that night , the 4th Indian Division gained a foothold south of Gemmano . It was finally captured by the 46th and 4th Indian Divisions on the morning of the 15th , and the British forces prepared to move toward Montescudo and exploit the German confusion . Battle . Entry into San Marino . The 46th Division took Montescudo on the 15th , and on the next day the 56th Division entered the town of Mulazzano , directly north of Montescudo and equally close to the border . The fighting pressed westward from here , with the 56th Division on the northern flank and the 46th on the south ; both were held back by strong German resistance . In early September , the German Army had sent a strong force into San Marino to " defend " it against the Allies ; this would also give them control of one of the major roads in the area , and allow artillery observers to occupy the mountain peaks . The defending force was drawn from the 278 . " Infanterie - Division " , whilst the 4th Indian Division was assigned to attack it on the 17th . The leading elements of the division — the 3rd / 10th Baluchi Regiment — crossed the Marano River on the eastern border on the night of the 17th , with the 1st / 9th Gurkha Rifles moving through them to attack Points 343 and 366 near Faetano . These small hills — just behind the river — were held by two battalions of the 993rd Grenadier Regiment . The first — Point 343 — was taken at 05 : 00 , but the force occupying Point 366 had to fall back after running low on ammunition . Rifleman Sher Bahadur Thapa was posthumously awarded the Victoria Cross for holding the crest of the hill single - handed for two hours , allowing two companies to withdraw in safety , before being killed whilst trying to rescue another wounded Gurkha . Point 343 was held through the 18th , however , though with the loss of 63 men ; by the evening , a force of tanks had managed to come up and stabilise the position with the aid of artillery support . The 4th / 11th Sikh Regiment moved around the Gurkhas to the north , covering the northern flank of the San Marino heights , and the division ' s 11th Brigade passed through them to help encircle the city . On the evening of the 19th , the 2nd / Queen ' s Own Cameron Highlanders of 11th Brigade began to push into the outskirts of the city from the north , but early on the morning of the 20th were held back by defensive positions in the north - west of the city , where the road to the upper part of the city , situated higher on the mountain , began . Tanks moved into the suburbs , whilst a company of the Camerons moved uphill toward the summit in heavy rain . The city was secured by the early afternoon , with only 24 casualties among the attackers , and 54 prisoners taken . On the 21st , the local defence forces were enlisted to help mop up straggling German troops , and the 4th Indian Division pressed onward through a heavy gale and passed out of the country . Aftermath . Allied forces remained in occupation of San Marino for a short period following the German surrender . In October 1945 , after the end of the war , the Sanmarinese government submitted a claim for 732 million " lira " to the British government for wartime compensation , of which 500 million " lira " were given as the related costs of the fighting in September and 20 million " lira " as the costs of the occupation . The British government rejected this claim , arguing that as Germany had breached the Sanmarinese neutrality before Allied troops had entered the country , it was not liable ; it did , however , offer an " ex gratia " payment of £26 , 000 in regard to the June bombing , later increased to £80 , 000 . The battle honour " San Marino " was awarded to three British Army units — the Royal Lincolnshire Regiment , the York and Lancaster Regiment , and the Queen ' s Own Cameron Highlanders — and two Indian Army units , the 1st / 9th Gurkha Rifles and the 4th / 11th Sikh Regiment . The latter three of these had fought as part of 4th Indian Division in the main attack , whilst the first two had had battalions in a brigade of 46th Division .